Where can I get an air compressor that can blow air (not just inflate tires)?

Here is a suggestion that may make some sense on several levels. Buy an air tank. I have a moderately big one, that holds 10 gallons of air. Of course, it is heavy to carry around, being steel. But when I need to pump up a tire beyond the range of the several hundred feet of hose I have, or for whatever use I need, I just disconnect it from my compressor lines where I have it coupled with a quick disconnect.

In your case, my suggestion is to pump it up with a foot pump. :) Ok, yes, this will take some work, but once pumped up, it will keep that air under pressure until you want it. And since you are looking for a "green" solution, this is as green as you can imagine, using foot power. Or, I suppose you could always just go to the local service station and pump it up to 100 PSI or so. Once the valve is shut, it will maintain that pressure for a long time.

Fix up a short length of air hose so you can use it to blow air. One of those plastic spiral air hoses might be perfect, allowing you about 20 feet of walking distance.

An even cheaper solution is to just buy a truck tire inner tube. Pep Boys sells them for about $15. Go to the gas station to pump it up, and then you can carry it anywhere you want, for a ready source of compressed air that weighs very little to carry around. Again, you will need to figure out how to put a line on the tire valve, but this is not hard to do. Go to your local hardware store and they should be able to get you set up. (I did not say to go to Lowes or Home Depot, but to go to a store where they actually understand hardware.)

EDIT:

Then here is what I'd do. The first part will be to put a hose onto an inner tube. I don't know what thread an inner tube valve is, so I would go to my local hardware store and get them to help me find a nipple with the proper thread. They tend to stock entire shelves of them, so this is not a real problem. Once you have that, you need to be able to couple it to a 1/4 inch NPT (National Pipe Thread.) This is a standard thread for air hoses and the like.  When you add the coupling to the tire valve, you will need to remove the needle valve inside. This will allow air to go freely in and out of the tire tube.

Next, add an Air line ball valve. This will let you shut off the air positively, because you want it to stay pumped up. Notice that the threads on the ball vavle are 1/4 inch NPT, exactly what you need.

Next, I went to Amazon and typed in "coiled air hose" into the search field. Typically, these run from $10 - $30, depending on the length of the hose. I find they work nicely, giving me an extensible hose. You don't need a long one though.

Finally, I looked online for a quick connect coupler. Central Pneumatic or Campbell Hausfeld  are common names here. The quick connect coupler will allow you to easily attach a handheld air blow gun as you show. Note that it will have a 1/4 inch NPT thread! You can also attach a regular tire valve, to use that to blow up your reserve of compressed air, using either foot pump or a gas station pump.

All of these items are common things you will find in any local hardware store, or even most auto parts stores.

Of course, the amount of air you can put into such a tube is somewhat limited, but it will easily be sufficient to keep a keyboard clean. You can put far more into a steel air tank, because you can store higher pressures there.


Can I use pressure treated lumber to build a wall?

Yes you can, but there are things you need to keep in mind. Pressure treated lumber requires hot dipped galvanized nails to fasten it in place. The treatment will rust regular nails to the point over time, they are worthless. So that being said, anything else you fasten to that material needs to be hot dipped galvanized or at least rated for use in ACQ/treated lumber.
As a mention, if you used them for the king studs and not the jack studs then the drywall or doors would have regular wood to fasten to. Just be certain to use the proper nails or fasteners to set it in place. No need to take chances


Can a quartz vanity countertop be recut for a larger sink?

You can take the unit to a granite shop and the shop will provide you with an answer like this.

"While it is possible to cut some quartz it is not a guarantee that it will cut properly. The possibility exist that the quartz will break or chip during the cutting process."

So if you are set on cutting it out - have it done .. and take the chance - if it does not work - buy a granite scrap piece.

Good luck..


Why am I having an attic ventilation problem this year when I didn't last year?

In case you haven't noticed, weather varies ;) This alone could account for the different effects each winter. But I think you're right, other factors are at play here.

Ventilation. Your gross vent area is 1/100 the attic area, accounting for louvers, let's say about 1/150th of attic area. If you do not consider the gable ends as cross ventilated, it is barely adequate. But as a cross ventilated arrangement, it is more than adequate. Will more help? Yes. Will it be effective? Harder to say. More on this later.

Moisture. Frost on nails alone is not necessarily cause for alarm. Black mold growing where the ventilation is less effective is definitely cause for concern. I'm no mold expert, but you should at least spray some moldicide on it while you devise a more permanent solution. Since the attic is always warmer than outside air, for there to be enough moisture to condense in the attic, the moisture had to come from either inside the house or from a roof or plumbing leak. Running a humidifier frequently would significantly contribute to the amount of moisture migrating into the attic. You don't mention anything about a vapor barrier, you quite likely do not know.The amount of moisture you observe tells me you don't have an effective moisture or vapor barrier. Not only can this cause mold, but it will also diminish the effectiveness of the insulation.

Why frost on only one side? Most likely solar access. The nails are colder on one side because the roof angles are different. This has significant effect on roof surface temperature, even under a good layer of snow.

Not only can vapor migrate through the ceiling, it can be carried in through air leaking around openings in the ceiling, in particular the pull down steps. If the perimeter is not weatherstripped, much moisture (and heat!) can escape this way.

What to do. Your primary focus should be to limit moisture migration into the attic. This will not only solve the condensation problem, but also limit heat loss. Seal all ceiling penetrations. Not only the steps, but plumbing and electrical penetrations as well. Apply an effective vapor barrier. This is not easy. You don't mention your ceiling finishes, this can make it easy or difficult or expensive. You could simply sandwich plastic between the current ceiling and a thin new ceiling finish. If you have an expensive existing finish, you may need to pull up the attic insulation and spray a barrier down on the back surface.

Note that if your household generates a lot of moisture, a good vapor barrier could cause you to have problems with condensation in your ceiling finish. The only solution to this is reduce moisture generation and increase whole house ventilation, ideally through a heat exchanger of some sort.

Once you've reduced the moisture migration, you may not have a mold problem in the attic any more. You may not need any more ventilation at all. The areas near the eaves obviously are not well ventilated, so the addition of soffit vents is the best approach if more is needed. You will need to drill many holes in the separation board to gain free communication with added vents.

If that works out to be too much effort, adding ventilation elsewhere can still benefit the lower areas, though not as well as soffit vents. Anything that increases ventilation will help. More static vents, power vents, ridge vents, turbine vents, they all have their own pros and cons, but they will all increase ventilation. You can do just one measure or a combination of measures. There is no right solution, but there is something that will make more sense than the other options.


What kind of pump would I need to supply my trailer with water from a nearby creek?

All this is contingent to your property having water rights to that creek. None of it is to be used as drinking water unless you like a good bout of liver flukes, giardiasis, cryptosporidia, hepatitis, typhoid, etc. Not a good idea to contaminate your RV water system with it.

What kind of pump? You start drawing vacuum on top of a 32ft column of water, so the pump will need to be a jet-pump if you plan on pulling water over 28 ft. vertically. Keeping the pump primed is going to be the bane of your existence if the water level in the creek drops below your foot valve.

A submersible in the creek would get rid of the vacuum issue and the priming issue in one, just don't let it run dry due to sucking your sump empty.

Conversion from head to psi is done by dividing vertical distance by 2.31 so the vertical rise from the pump to your tank system needs to be known. 100 yards on an incline isn't the same thing as vertical rise. Figure rise in ft./2.31 = psi required for the pump to produce to get it to the gravity tank. (how to figure vertical rise below).

Figuring the head needed to give you pressure at the RV requires multiplying psi * 2.31 = rise in ft. so if you want 20psi at the RV, 20psi * 2.31 = 46ft which means your tank needs to be 46ft higher than your RV.

To figure the pressure available at your sprinklers, measure the elevation change from the tank down to the garden, drop in ft./2.31 = psi available to run your sprinklers.

For controls, you need to have a float switch in the gravity tank to keep from overfilling and a way of monitoring for when the creek runs dry to shut the system down so you don't burn the pump out (not mentioned where on the planet you're located).

None of this takes into consideration the amount of wire you need to run down to the pump or the sizing of the wire to reduce voltage loss. It'll have to be 220V to keep the current down, so no 120V pumps. And it will need to be run through a piece of pipe to keep the local wildlife from deciding that Romex is tasty. Squirrels love it.

Any springs or small tributaries uphill from your location? A 1000 gallon stock tank and gravity from there are a lot less energy costly.

Addendum Simple trig for real life or how to figure something you can't measure with two items you can.

You get a protractor, mount it on a stick you can push into the ground, make sure the flat side is level with the angle measurement side down and then sight along from the apex (pencil hole if you're using one of those cheap plastic ones) down to the pump location. Now you measure the distance on the ground from your protractor apex down to the pump in as straight a line as you can possibly achieve following the sight line.

This gives you a right triangle with a known hypotenuse and an angle. You now want to calculate the height of the opposite side.

If you have Windows, you have a scientific calculator function that can be turned on from one of the dropdown menus. Set the angle function on it to Degrees, enter your angle and click the sine button.

Multiply that by the distance you measured and you should now have the vertical distance between the pump location and a sight line straight out from the RV location. This is the vertical head your pump will have to overcome to get water up to that elevation. As discussed, you will need to place the tank yet further up the hill to have any appreciable pressure at site, so you probably want to measure at that location instead.


Can I configure a two-stage thermostat to manage two heat systems?

I have almost the exact same setup as you (hydronic floor heat and air handler for backup heat) and mine works with one tstat just fine.  So while you aren't asking for too much from "a" thermostat, you may be asking too much from "that" thermostat.  I looked at the specs and didn't see anything about 2nd stage heat or aux heat, it might be there but I couldn't find it. On my tstat it's call "aux heat". I think 2nd stage heat is for a 2 stage furnace or heat pump. When the more economical first stage can't keep up or you've turned up the heat a lot, the 2nd stage kicks in on the same device.
I think Aux Heat means a different heating device.   Ed Beal could probably contribute more here.
Anyway, I run a Honeywell RTH8500D.   And it does the job you want. I didn't hook it up, so can't give you the specifics on that. But what you want can be done and this is the tstat that works for me.


solution : a french drain around the perimeter, depth of about a foot or so below where your water line is . this entails digging a trench, drying out any moisture, then applying bituthene to the wall before filling the trench with rock . the bottom of the trench should angle down from wall to yard, so water will drain through the rocks then away from the building


If it would previously turn either direction and now does not , this is indicative of either something physically blocking the mechanism inside or needing lubricant. Either way your solution is the same- disassemble and lubricate. Remove the knobs, then remove the latch assembly. Remove any obvious pieces of metal or debris that are present, add a lubricant, work the mechanism, and reassemble.

https://m.youtube.com/watch?v=WX8NG0275R4


Does overspray get on the ceiling when spraying interior wall?

You will definitely need to mask off the ceiling, over spray gets everywhere.....


GE OTR Microwave Model: JVM1850SMC02 - Doesn't power on, not even display lights

I'd be more inclined to suspect a bad interlock or possibly a dead triac than a capacitor failure -- either way, microwaves are best taken to a service tech to be serviced (they're one of the few household appliances that contain a truly lethal HV supply in them).


How do I prevent my fence gate from binding against the post?

First, determine why it is binding:

Is it because the wood has swollen due to wet weather, pests, etc.?
Is it because the posts surrounding the gate have shifted?
Has the ground shifted and moved the posts closer together?

My garden gate binds during wet weather.  Fortunately, we are much less likely to use the gate then.  The posts and gate are set to match perfectly when the wood is dry and that is when we most care about it working well.

If I were to do anything to make "wet closing" easier, I would bevel the striking surfaces so they wouldn't cause a dead stop, but move the posts apart so the gate can be closed with one hand.


When insulating a new house does the poly have to be caulked and taped at the top?

Unless you live in Canada, Alaska, or a similarly cold and moist climate, you neither need nor want interior poly, especially if the climate is rainy, if the house will ever be air conditioned, if you are using OSB or fiberboard (e.g. Celotex) sheathing, if you're applying stucco or adhered brick or stone right over the sheathing with no rainscreen gap, and ESPECIALLY if all of those are true. Just Say No.

For more info on this subject, see the following:

http://www.greenbuildingadvisor.com/blogs/dept/musings/when-sunshine-drives-moisture-walls

http://www.buildingscience.com/documents/reports/rr-0104-solar-driven-moisture-in-brick-veneer

http://www.greenbuildingadvisor.com/blogs/dept/musings/do-i-need-vapor-retarder

http://www.greenbuildingadvisor.com/blogs/dept/musings/vapor-retarders-and-vapor-barriers


Is this cracking foundation under a jack post a problem that requires repair?

I'm not familiar with USA house construction methods (I live in the UK) but speaking as a mechanical engineer, I wouldn't even stand near that thing while debating how safe it was.

That bolt is presumably supposed to be fixing the post against it popping out sideways. I suppose it was meant to be bolted to a metal beam underneath the concrete. So either that whole beam has sunk, or all the rest of the concrete floor has heaved up for some reason (ground water underneath. maybe?) or there isn't any beam there at all, and it's just an undersized-looking bolt sticking into a bit of broken concrete.

It looks to me like it's just waiting for the right moment to make a nice loud PING as the post flips out sideways and the whole floor above it collapses.......

One more thing. That metal post didn't get longer by magic. So if it has pushed a hole in the floor, whatever is on top of it must have settled. That could mean the whole house is sinking unevenly for some reason.


Why did my surge suppressor make a "pop" sound when I plugged something in?

Popping sounds are generally either a sound from a spark, or a failure of an electronic component. They do not always mean that something failed. For example, plugging in electronics that use lots of power will often cause a small spark to form when plugging them in. As an example, my Lenovo laptop power adapter will often make a sparking noise when I plug it into an outlet and it is not a cause for concern.

Does your power adapter create such a noise when using other outlets? If so, then you may not need to worry at all. See this question for some more details on this transient arcing.

But, sometimes noises do indicate failures, for example when a capacitor, MOV or IC explodes. You could also hear a click when a circuit breaker trips, but this would cause a circuit in your house to be no longer be energized. Some power bars also have internal circuit breakers, which can also make a click when they trip.

In your case, I'd first say that a used surge suppressor probably may not provide much protection for your electronics. If you are concerned about surges, you should look into verifying that your house has a good ground, installing a whole-house surge suppressor, using quality surge suppressors where your electronics are installed on both the power lines and data lines such as telephone or CATV. Surge suppressors do age, and can only handle a certain amount of surge during their lifetime. Ensure that new surge suppressors meet the new UL standard 1449 v3 by checking for a holographic sticker that says "Surge Protection Device".

Now to your other questions:

2) This should be safe. Any over currents should be protected by your house's circuit breakers, and a lamp is a pretty "robust" device that wouldn't be seriously damaged by a bad power supply (though the bulb may burn out). That said, do this in an area where if the power strip catches fire, it won't damage anything, and you could quickly pull the plug out of the wall socket if something bad happens. Don't put water on an electrical fire.

3) As I said above, the power bar may not provide significant surge protection, especially now that it may have failed. You may want to dismantle it (while it is unplugged) and see if there are any burnt/charred/damaged components.

This answer is more of a matter of opinion. To be safest, you could replace it with a high quality surge suppressor, but with some investigation, it is likely as safe to use as any other power bar.


I have older HVAC unit (heat pump) and looking for the C wire to hook up to Smart Thermostat

You need a "Power Extender Kit (PEK) from Ecobee. I am surprised that the PEK wasn't included in your purchase of the smart thermostat. Mine was.

Visit their web site at

https://support.ecobee.com/hc/en-us/articles/234707528-ecobee3-lite-with-PEK-for-HeatPumps

Their web site also has a "Live Support" ; or, you can call them at 1.877.932.6233.  They provide very good support service.

Sert


This is probably due to a bad or unlubricated drum roller. Look up the service manual for your dryer to get access to these rollers, but a generic diagram is below.

Note that many dryer drums are not suspended from the center, but rather rest on a few rollers, front and back, beneath the drums. If there's friction in the roller, it might not contact the drum for the whole rotation but makes periodic, squeaky, contact.

Inspect the rollers. If the rubber wheel is deteriorated, a replacement roller and belt kit might be about US$40, depending on dryer model, or look for just individual rollers. If the wheels look good, you could apply one or two drops of motor oil to the shafts. Caution: oil, lint and heat can lead to a fire, so vacuum the dryer thoroughly, and be sparing with the oil, which could also destroy the rubber belt.

If the dryer is more than a few years old, I'd suggest getting the correct roller replacement kit, rather than an individual roller, whatever the condition of the roller wheels, replacing only the bad one(s), keeping the rest until another breaks.


Electrical receptacle inside kitchen cupboard? (California code)

You should be able install a receptacle inside the cabinet, I'm not aware of any code that says otherwise, and the code you quoted describes the minimum requirements. It's often done for garbage disposals, dishwashers, and over the range microwaves. Using an extender ring is probably the easiest way, so you don't need to predict exactly how far the outlet box needs to be installed from the wall. With some cabinet installs, it may be so far out you wouldn't have a proper nailing surface for the outlet to the stud.


What preparation is needed to apply knockdown ceiling

I assume that you have a fairly rough surface at this point. When I refurbish texture over a large area I do a full skim finish first. If you want your texture to look new and professional you can't go over a mess. Standard or topping joint compound work well.
So, skim, scrape any ridges, and skim again. Repeat until it's like new, then sand lightly.


Wiring a receptacle from a ceiling box in a basement

Since this is a ceiling box the wiring is probably designed for a light fixture. As such it will have a neutral (which would be the white wires connected together, but it may have only a switched hot and not a line hot (which is always hot). But it is possible that it contains a line hot. The first task would be to find out if you have an always hot in the box.
With the wires connected as they were originally use your non-contact tester to see if the bundle of black wires is hot in all the wall switch positions. Also test the red wires. Record and report to us.
You say you want to use this box as a source for an "outlet" which I take to mean you want a receptacle to be powered with an always hot and a neutral from this box, right?
EDIT1
Use a pair of "pigtails" one white and one black to connect to a receptacle.  The white pigtail connects the bundle of connected whites to the neutral side of the receptacle (the longer slot); the black pigtail connects the bundle of blacks to the hot side of the receptacle (shorter slot). Unless this us a grounded receptacle in a metal box, use a green or bare pigtail to connect the ground wires to the ground screw of the receptacle.
EDIT2
To get maximum use of your wiring you should determine if the black and the red are part of a "multi wire branch circuit".  You have said both are hot, but are these two wires switched by the same 2-pole breaker in your panel? Or are they each switched by one of a pair of linked (handle tied) 1-pole breakers in your panel?


Foul smell in my bathroom when I run water anywhere in my house

First I'd want to confirm that it's really from the waste system (as I would think).  When there's no smell, plug another sink and run water to put some in the basin.  Stop and verify still no smell.  Then drain the basin and see if the smell arises.  If that happens, you can be sure it's related to the waste system.

Can you plug the sink temporarily (both the drain and the overflow)?  If you do so, does that prevent the smell?  It would be nice to isolate it to a single location.  Is there a tub/shower?  Could it be coming from there?

If it's from the sink, I'd think there's either improper venting or incorrect p-trap in the bathroom.  Can you show a picture of the pipes under the sink?  If it's not set up correctly, then water running down the pipes from elsewhere can siphon the water from the p-trap, allowing sewer gases to escape the drain.


City replaced water meter, then bathroom sink pressure dropped, rusty water

You're right--some metal was jarred loose by the work on the meter and the resulting pressure shock. What you weren't able to clear out already is probably stuck in the aerator screen (or flow reduction disk, if present).

Unscrew the cap at the faucet outlet. There should be a mesh screen there, and possibly a perforated plastic disk. Pull them out and rinse them. Run some water through the faucet without the screen and disk.

If that doesn't clear it up you'll probably need to disassemble the faucet. That's not usually difficult, but may involve replacing some o-rings or seal seats. Most faucets made in the last 15-20 years will have replacement parts available at hardware stores.


Product & technique recommendation to trim this door

Purchase a 1" thick by 3 1/2" wide PVC trim to go around the 3 sides of the door. Ripping to width were it fit to a proper set back from the edge of the jamb in all areas below the masonry cap of the walls. In essence, trimming in out in a typical fashion the way interior doors are trimmed.

A thinner trim would work but the thicker trim allows the back side that meets the rough wall to be cut out so it goes over the irregular surface. With care the edge that will meet the door jam will remain full thickness, keeping that joint looking as clean as allowable, provided the conditions you are working with.

I would use PVC over the choice of wood since it is impervious to rot.


I couldn't identify any breaker with only two white wires, but the 10 breakers at the bottom each have two white wires plus one black. This is because they're arc fault (AFCI), ground fault (GFCI), or combination of the two functions. Those kinds of breakers have to monitor the current through both the neutral and the hot lines. The white jumper from the neutral bar to the breaker makes this possible.
The breakers that have only one black wire connected to them are conventional breakers. The neutral wires corresponding to these are attached directly to the neutral bus bar.
The connection of the new all-in-one breakers is just as you said. The white pigtail should connect to the neutral/ground bus bar, and the ground conductor from your new circuits goes there too. If the pigtails aren't long enough you can extend them with a piece of same-gauge white-colored wire joined with a twist-on connector (aka wire nut). Then the black and white wires from the new circuits go to the line and neutral terminals on the breakers. Position matters; the breaker will be marked in some way to indicate which terminal is which.


Replacing 2 dimmer switches, breaker keeps tripping?

Congratulations, you've created a short-circuit.  You've connected the ungrounded (hot) conductor directly to ground through the switch.

the reason the second switch caused the breaker to trip, is because it was toggled in the "correct" orientation.  If the other switch had been toggled, it to would have tripped the breaker.

What you need is a single pole switch, not a 3-way.  Then you'll connect the green wire to the green grounding screw, and the hot wires to the other brass colored screws.


I had this recently with a recently installed Tado thermostat and 8-year old Horstmann diverter valve.

The valve was found to be sticking, The thermostat was fine.

Yo can check this by unscrewing and lifting the diverter head off the valve, the turning the valve to the hot water position with pliers.

In my case, the radiators started to warm immediately.  Putting the head back on the valve reinstated the hot water only situation.  Moving the manual override lever on the valve head had no effect.

A new diverter valve fixed the problem.


Are electrical screws a standard diameter?

There's no reason it would not be a locally standard size (given a British location based on the label, presumably metric or pre-metric British Standard threading) so some basic measurements (no calipers required, if you are willing to use a ruler carefully and buy 2 or 3 nuts, one of which will be the right one) and a trip to the hardware store should find a nut to fit.
You might also try putting fine net mesh over a vacuum cleaner inlet and vacuuming for the nut, first.


How do I choose a recessed alarm contact switch?

I'm looking at doing the same thing in my house later this year. But, I want to emphasis that drilling through your windows/window frame can void your warranty. If these are new windows, you'll want to have that warranty in place just as an "what if" happens in the near future. You'll have to refer to your warranty documentation to see if drilling will void your warranty.

The Ademco 3/8" Diameter Miniature Press Fit Magnetic Contact looks pretty standard. Just to be on the cautious side, you can always measure your frame to see if you have enough space. Otherwise, I see no issues with installing these on your door and the frame. Also, I've seen them installed on the top of the door or the side of the door. That's your call.

You may want to re-consider and utilize non-recessed/surface mounted contact switches for your windows and its frame. First of all, research more about your windows. If they contain spring mechanisms in the inside of the window or the window frame, then you will not be able to drill a hole. Otherwise, if there are no physical obstructions, then you can normally drill the required diameter near the bottom of the window. You want to make sure that the hole is covered and not exposed to the outside environment. If exposed, you could use some sealant to protect the contacts. Also, if your windows are double-hung, you'll need contacts installed at the top and the bottom of the window. You can connect the two contacts in a series so that you don't have to run two sets of wire to the control panel.

All the recessed options you provided are for different scenarios of windows/doors. Normally, regular sized contacts are used except where these sensors may be too large to fit the door or window frame. Stubby contacts would be used in such occassion. The stubby/earth magnet contacts are great for window applications because of the size of the magnet (depending on your window type, you may not need to drill into your window to fit the magnet).


Why have my ceiling fans started running slower?

The fan itself is on low speed. Pull the chain, twice. Once will turn it off. Once more will set it to high.


How far should my wall be from my furnace/water heater?

According to International Residential Code (IRC), you'll need to provide a 30" x 30" level working space for servicing and inspection of both appliances. You'll also have to follow the manufacturers installation instructions, for clearances from combustible materials and any other restrictions.
You'll also have to consider supplying the equipment with adequate combustion air, and supplying the air from an appropriate source.
Working Space

International Residential Code 2012
Chpater 13 General Mechanical System Requirements
Section M1305 Appliance Access
M1305.1 Appliance access for inspection service, repair and replacement.
Appliances shall be accessible for inspection, service, repair and replacement without removing permanent construction, other appliances, or any other piping or ducts not connected to the appliance being inspected, serviced, repaired or replaced. A level working space at least 30 inches deep and 30 inches wide (762 mm by 762 mm) shall be provided in front of the control side to service an appliance. Installation of room heaters shall be permitted with at least an 18-inch (457 mm) working space. A platform shall not be required for room heaters.

Water Heater

International Residential Code 2012
Chapter 28 Water Heaters
Section P2801 General
P2801.2 Installation.
Water heaters shall be installed in accordance with this chapter and Chapters 20 and 24.
P2801.3 Location.
Water heaters and storage tanks shall be installed in accordance with Section M1305 and shall be located and connected to provide access for observation, maintenance, servicing and replacement.
Chapter 20 Boilers and Water Heaters
Section M2005 Water Heaters
M2005.1 General
Water heaters shall be installed in accordance with the manufacturer’s instructions and the requirements of this code. Water heaters installed in an attic shall comply with the requirements of Section M1305.1.3. Gas-fired water heaters shall comply with the requirements in Chapter 24. Domestic electric water heaters shall comply with UL 174. Oiled-fired water heaters shall comply with UL 732. Thermal solar water heaters shall comply with Chapter 23 and UL 174. Solid-fuel-fired water heaters shall comply with UL 2523.

Furnace

International Residential Code 2012
Chapter 24 Fuel Gas
Section G2408 (305) Installation
G2408.5 (305.8) Clearances to combustible construction.
Heat-producing equipment and appliances shall be installed to maintain the required clearances to combustible construction as specified in the listing and manufacturer’s instructions. Such clearances shall be reduced only in accordance with Section G2409. Clearances to combustibles shall include such considerations as door swing, drawer pull, overhead projections or shelving and window swing. Devices, such as door stops or limits and closers, shall not be used to provide the required clearances.
G2409.4 (308.4) Central heating boilers and furnaces.
Clearance requirements for central-heating boilers and furnaces shall comply with Sections G2409.4.1 through G2409.4.5. The clearance to these appliances shall not interfere with combustion air; draft hood clearance and relief; and accessibility for servicing.
G2409.4.1 (308.4.1) Appliances clearances.
Central-heating furnaces and low-pressure boilers shall be installed with clearances in accordance with the manufacturer’s instructions
G2409.4.5 (308.4.3) Clearance for servicing appliances.
Front clearance shall be sufficient for servicing the burner and the furnace or boiler.


Why does single pole light switch have 3 wire cable when source is at the switch?

This circuit is being fed forward from this location.

The two blacks are constant hot, the red is switched hot.

If you follow the /3 when you get to the other end of it, the red is switched hot, the black is constant hot.

Edit to add:

If this switch is feeding a ceiling box, this is a common configuration so that the light switch (red wire) only controls the light portion of a ceiling fan, allowing the fan itself to be controlled separately by the pull chains.  If there is currently just a light fixture, then they only used the Red switched hot wire, and capped the black.  The circuit could also, optionally, continue forward from the ceiling box using the black-constant hot, and white-neutral.


How can I muffle a speaker on a small TV?

An alternative to duct taping a towel over your monitor speaker would be to:
Get a used A/V receiver at a thrift shop that has HDMI in/out.
Go >HDMI from Apple TV and Blue Ray >into the A/V unit and HDMI> out to the monitor.
A set of speakers connected to the A/V unit will handle the sound.
Volume control on the A/V unit will adjust the sound to the speakers.
Easypeasy macandcheesy. OR, Bobs your uncle. Depending on what side of the pond you are on.


Help Critique deck post and beam location

I am not a structural engineer but i have built decks so take my opinion for what it is worth.  Your post spacing looks good, But we do not know what size beams you are using and that matters in order to know if they are adequate.

I would move your first beam in towards the house 2' so it is 8' from the wall. That way each joist run is 8'

2x6 for joist is inadequate. Your long run of joists ( 10 feet ) will require  that your joists be at least 2x10 lumber.

I might use 16 foot joists so they run over both beams instead of having  the first beam be a double ledger.

There are online deck calculators that you plug in your dimensions and it will tell you what size joists and beams and posts specs you need.


help with improving HVAC performance on the second floor of an old house

I've been the HVAC industry for more than three decades. To answer both of your questions: The ideal installation would involve installing a return and a supply to each room. This allows you to accurately and more precisely control the climate in each room. The answer to your second question: Yes, you will need to insulate the ducting outside the insulated envelope of your home. If you do not insulate the ducting it will sweat, causing water damage to your home. Home this helps. Hope I answered all of your questions. P.S. Shop around and hire a legitimate HVAC contractor who will size your equipment properly or you might get stuck with the wrong size HVAC unit. Good luck to you and congratulations on your growing family!


Will security system wiring cause interference in data cables?

TL;DR it should be OK to run them together.

The signals from a security sensor are typically very low frequency because they're generated by the switch within the sensor opening and closing as the sensor activates.  So for a motion detector, it might open and close a few times as you cross the field of view; a door or window sensor would switch as often as you open or close its corresponding door/window, etc.

The signals from a remote keypad are higher frequency because they have to communicate more information, e.g. the text to display on the screen, or which buttons were pressed on the keyboard, but they're still going to be low frequency1.

Twisted pair cables, such as Cat 6, are fairly immune to outside electromagnetic interference, and coax is even better thanks to its outer shield.  And since the signals they carry (e.g. Gigabit Ethernet, TV signals, etc.) are very high frequency, the chances of interference with the security system's signals are very low.

1. The value 300 bits/second is emerging from my long-term memory, but I could be conflating it with the speed of the soft modems on security panels


I am replacing a burned upper thermostat to my water heater. How do I replace the wire leading to the thermostat?

Before you replace the wire test it to see if it is damaged. First shut the breaker off to the water heater. Next separate the power cable from the water heater wire. The water heater's power wire usually runs to the thermostat. Remove it from the terminal screw. With a continuity tester touch a lead to each end of the black wire which should show continuity. Next with one lead on the wire touch the other to the metal tank and outer shell. You should not see continuity (which is good).
If you do need to replace a wire: with the power still off, tape the new wire around one end of the old wire securely and slowly pull the other end of the old wire until the new one reaches where it will go. Use he old wire as a lead to pull new.


What is the plumbing diagram symbol for a water hammer arrestor?


7 wires, 3 sources, switchable power in 2 wires - how to put it back?

I tried to test out different combinations, blowing up a fuse in the process. In the end I gave up and called an electrician.

He figured it out by testing out which wires make a circuit with the wall plugs. He had some sort of multimeter for testing it.

I believe the wiring was done similar to the following diagram (while ignoring ground wires):


Thermostat fan control on old furnace without circuit board

You will need to add a 24 volt relay that is controlled by the green wire and a common and wire the relay contacts to bring on the fan by jumping the contacts in the 4064 fan/limit control. You can use a RIB relay or similar one.This is how it was done in the "old days".


Warehouse Lighting Wire Size Calculation

Thirty 42-watt fixtures are nominally 1260 watts, which is 10.5 amps at 120V.

Your longest run has the lights evenly spaced between 150' and 310' and the halfway point between is 230'.

Hit a voltage drop calculator

Set it for 5% voltage drop, as your lamps can handle that... and ask it for at least 3 points:

10.5 amps (max) at the 150' (start) distance
8 amps (3/4) at the 190' (1/4 way) distance
5.25 amps (half) at the 230' (halfway) distance

TLDR: I get 12AWG for each of those calcs.

For each test, the calculator will recommend a wire size and give you the expected voltage drop to be found there. Its recommendation is applicable from the panel to the point you asked about.

They say to use 3% voltage drop, but that is silly, 5-6% will work fine. But don't push it to 10% (unless you really want to) because if you upgrade to multivoltage lamps, those will answer voltage drop by drawing more current in proportion, throwing calculations off.

Is voltage drop OK?

It's not unsafe to have high voltage drop.  The 20A breaker definitively protects your 12 AWG wire if your wiring methods are legal. (an example of "illegal" would be more than 9 conductors in a single conduit without derate). Of course the voltage drop is heating the building.  Electric heat is a fairly expensive heating method, especially if you're trying to air-condition the place!  So get out the sharp pencil and figure out the voltage drop, multiply by amps to get watts, figure the cost of the power and additional A/C load, and see if you can cost-justify thicker wires.

The voltage drop calc will keep you legal -- however it doesn't know about your 20A breaker.  14AWG wire is never legal downstream of a 20A breaker, 12 is your minimum.

Did you catch the part about "9 conductors per conduit"?

That's kind of an issue.  If you want to cram 12 circuits in a single conduit, that is 24 conductors. That requires a 45% conduit derate, forcing you to 8 AWG wire.  Don't do that, unless you would anyway for other reasons.

It might help to re-label your circuits as 15A circuits and fit 15A breakers. 10-20 wires per conduit would be legal with 12AWG wire on a 15A circuit.**  You can only have 12A of continuous loads on a 15A circuit, but you are under 12A.

How do big warehouses work around this?

Multi-wire branch circuits.  In an MWBC, the neutral does not count as a conductor since it only carries differential current. With 120/240 split-phase, you can get 4 split-phase MWBCs (8 hots) in a single conduit without derate.
Three-phase "wye" MWBCs such as 120/208 "wye". This adds a third "hot" conductor.  With 3-phase, you can fit three MWBCs (9 hots) before hitting the derate limit.
277V voltage.  With 277/480 3-phase, you can get more than double the power in the same conduit.

Combine all these tricks, and a single 1/2" conduit with twelve 12AWG wires can carry 39,888 watts** - enough power to light up an entire CostCo.  (that being 9 circuits x 277V x 20A x 80%, the latter the continuous derate).

** why is this? The 50% derate comes off the 90 degree C column in the table, so 12AWG is 30A@90C. 10-20 wires calls for a 50% derate, or 15A.  (and just so you know, 7-9 wires does require a 70% derate, but 70% of 30A is 21A... and 12AWG is limited to 20A for other reasons.)


Ceiling fan on one circuit tripping GFCI on separate circuit

Try a Lamp Debuzzing Coil on the line-side of the dimmer

This sounds suspiciously like your dimmer is generating some sort of switching trash on the power line that's interfering with the GFCI's circuitry and causing it to trip, since it only happens if you change speeds.  The general fix for this sort of interference problem is to wire a Lamp Debuzzing Coil (LDC) (which is a prepackaged choke, basically) in on the line side of the dimmer, as documented in Lutron appnote #519.

If it persists, change the GFCI out for a new one of good quality

If the Lamp Debuzzing Coil doesn't fix it, then I would keep the coil in place (it'll cut down on RF trash coming out of the dimmer in any case) and replace the GFCI with a new one of good make and quality (you want a specification or industrial grade GFCI receptacle or deadfront device here, not the cheapest builder-grade thing you can find).


I have 2 outlets from front and back of the house that have no current

Since outside receptacles have required GFCI protection for a long time there is probably a GFCI receptacle inside the home that is protecting these.
With the receptacles required at front and back they are quite often fed from a receptacle close to the door that is a GFCI. Reset this and they will probably be fine. Sometimes the receptacle inside is on the other side of the wall.
Prior to WR rated GFCI receptacles it was common to put them inside. After weather ratings became a thing it made more sense to put them outside as the moisture no longer was a problem (the electronics are potted) this is an encapsulated coating that seals the electronics from moisture.
You might also check for switches as many outside receptacles are put on switches so they can control holiday lighting.


Why does my kitten's urine clean my carpet?

Urine (human and animal) contains ammonia, paricularly if it's left for a while, e.g. if you didn't notice it at first.  Ammonia is used in carpet-cleaning products.  In fact it's been used for stain-removal since Roman times.
You might want to track down an ammonia-based carpet cleaner, but use it when you can open all the windows and sit outside for a bit afterwards.


How do I remove black rings on a wood kitchen top formed by a tin can?

Oxalic acid, either in crystal form or as part of a pressure treated deck cleaner/brightner will chemically dissolve the stain.  If you use the crystals, use all normal precautions for acids (eye, hand, clothing).  You can sparingly apply with a small nylon artists brush.  Try 5 min increments (5 on, wipe off, 10 on, wipe off) until the stain starts to disappear.

Once stain disappears, neutralize wood with borax diluted in water or bicarbonate of soda in water.

Replace color with dyes or pigment stains.  I like Transtint for its ability to be blended and mixed with either water or alcohol. If you don't like the color direction, you can use bleach and start over.

Once happy with the color, seal it in with a dewaxed shellac.  Then top coat with your favorite polyurethane.  You may be able to blend the areas by shooting spray poly through a circular mask (5" hole in a 12x12 piece of cardboard, held 5-10 inches away from the floor) which will give you a graduated spray.  Practice first.


Low Frequency Hum - exactly 30 minute duration at random times

Could it be a sump pump in your building and the discharge pipe is touching framing.


Furnace end bell burned out twice in 4 years

It sounds like you have an ECM "constant flow" blower that ramps up output as high as necessary to maintain the set airflow (aka an ECM constant torque motor).  A MERV 11 filter is too restrictive for most residential systems.  In this case, the motor would compensate for the restrictive filter by running harder and hotter to maintain the airflow.  Switch to a MERV 8 filter (it's still a pretty good filter).  If your system delivers more airflow than you need, then also set the airflow selector switches in the furnace to a lower setting.  Obviously the air filter should also be changed regularly before it becomes plugged or the blower will again ramp up to a very high level to compensate.

EDIT; Specifics related to OP's situation:

It turns out OP has a very high performance MERV 11 filter which if correctly matched to the system might be OK.  The stamp on the side of the filter states "Airflow Capacity up to 1400 CFM."  In reality I would expect this to mean this filter might be successfully employed on a system with a 3 ton cooling capacity (3 tons / 1200 cfm).  It would not work for a larger system.

I found more detailed information on an air cleaner that uses OP's media here:

http://www.cleancomfort.com/assets/Brochures_SpecSheets/Filtration/SS-AM11-3225.pdf

The referenced unit above uses two (2) AMP-M1-1056 filters and therefore handles twice the airflow of OP's setup.  In my experience a pleated filter is near its end of life when the static pressure drop reaches about 0.2" WC.  Looking at the "AM11-3225-5 Pressure Drop vs. Air Flow Rate" chart on page 2, one sees 0.2" static pressure loss corresponds to 2600 CFM for two filter cartridges when new.  So according to this chart, 1300 CFM would be the max airflow through OP's one cartridge when new and if one were to run the filter at that high a flow it would need to be changed very frequently (at least monthly?) because it would become more restrictive as it filled with particles.

My conclusion:  If OP's system does not exceed 3 tons / 1200 CFM and OP changes the filters monthly (normal intervals of 3-6 months are plausible if the system is 2 tons / 800 CFM or smaller) then the existing setup is probably OK.  Otherwise switch to something less restrictive.


feeding both sides of load center from 120vac backup source

No "checklists"! Hard-built interlocks only.

There is no such thing as "making sure your main breaker and 2-pole breakers are turned off".   You must not do generator interlocking via a checklist or procedure.

There are only three legitimate ways to switch from mains to backup power:

a generator-style interlock or transfer switch
"permanently" rewire the panel or circuits so they hardwired to power off the alternate source only,  and no longer are able to power from mains. When power returns, "pemanently" wire them back.
switch the loads via cord-and-plug connection.

The cheapest and simplest way to implement a generator interlock is, if an interlock kit isn't made for your main panel, to get a no-lug subpanel with an inexpensive interlock (Murray or QO) and have two backfeeding breakers back to back interlocked, and then put the loads you want to switch into this panel.

Go ahead and feed both poles, except...

Once you have done this, go for it.  Go ahead and split your 120V supply so it feeds both legs of the interlocked 240V "generator" breaker.

... except Multi-Wire Branch Circuits

However, this will be very bad for multi-wire branch circuits (MWBC).  These are circuits which share a neutral.  The hot wires must be on opposing poles so the neutral only handles differential currents.  Putting them on the same pole will mean neutral handles the sum of both hots' currents, and that can overload it.

How do you avert this? Ideally, you put your to-be-gen-powered circuits in a separate subpanel (again, the cheap way to provide that gen interlock)... and simply don't migrate MWBCs to that panel.

Or go on a crusade to eliminate all multi-wire branch circuits,

At the very least, you identify in advance your MWBCs, by going through your panel, finding them, and placing them on 2-pole breakers.

Notably,  a "make turning off MWBCs part of your checklist" apparently violates the "no checklists" rule.   However the main reason for that reg is so you don't kill linemen, who are innocent outsiders.  I am not sure if Code has taken a stance on this entirely local consequence.

What will happen if you power a 240V appliance?

A 240V appliance (water heater, A/C): Nothing.  Every conductor in the appliance will be at the same potential, so no electrons will move. This will happen to be 120V from safety ground, but who cares.

A 120/240V appliance (dryer, range): The 120V parts of the appliance will power up (tumbler, timer, clock, oven light).  The 240V parts, see above.   So for instance your dryer will work, but only on "fluff/no heat".


What's the best type of underlay for bamboo flooring

I hate to be the bearer of bad news, but particle board is not a good choice of subfloor, unless it has gotten better over the years. (It has, at least in Australia, see edit below)I asked the question of floor suppliers and here on SE about fastening flooring to particle board with an answer that said nobody will guarantee the floor will stay in place.

Your picture of the floor was very dark, but it did look like it was 3/4" T&G nail down. If your subfloor was plywood, you can go directly over the subfloor, no underlayment needed. It looks like you may need to screw and glue down a plywood underlayment, 1/2" would be my choice, but others may have had luck with thinner, over the particle board floor to keep the fasteners in place that hold the bamboo floor.

Edit

You need to look over the install guide for the yellow tongue, it appears it can have flooring nailed directly to it. It uses some terminology in the guide that I am not familiar with. I can guess what it means, but the idea I get is that you do not need to place an underlayment over it like I originally posted. But you need to read the install guide to determine it too.


What is the best/cheapest solution for poorly plastered walls?

The best solution is to get them replastered. However, this is a messy and expensive job as you need to hack off the old plaster first. The expense comes from hiring a plasterer.

The cheapest solution is to cover them with drywall. This will give you a nice smooth wall.

You can glue the drywall directly to the plaster which will work if the current plaster is not too uneven. A better finish will be obtained if you batten the walls first ensuring that the battens are vertical and level horizontally. However, as @Tester101 points out you'll have to "pull out" all your sockets and light switches and have issues around door and window frames.

A better solution would be to rip the plaster off and then plasterboard, again either gluing or battening depending on the quality of the wall. Battening would allow you to add insulation and/or a void for feeding any cables you might want to add (ethernet, coaxial, power) in the future. This is still messy, but should be cheaper.

Sanding is possible, but it will generate a lot of dust and is a lot of effort for indeterminate results. If the plastering isn't too bad you might get a good finish, but you will have to skim the walls again to get a really smooth finish.


Why would our kitchen faucet hot water stops working intermittently when it gets cold outside?

Hot water line is closer to the (substitute "source of cold" for "outside wall" in my comment) than the cold water line, and freezes first.

Mysterious water stoppages in cold weather are nearly always from pipes freezing.

The fact that it's the hot water line does not mean that it's full of hot water - after it's sat for a few hours, it's cold, and if it's sat for a few hours by something really, really cold, it will freeze.

Some plumbers can be quite oblivious about this - I've seen pipes clamped to the inside of the sheathing and all the insulation being put on over them - I've also seen those supply pipes, which I was assured would never freeze when I pointed it out, relocated to coming up through the floor inside the wall after a cold spell (not my house, someone else was "in charge" and it evidently took the pipes actually freezing before they would do the job correctly. It probably cost 3 times as much to do over as it would have to do right in the first place.)


How do I add a switch/light and two outlet from a single power source?

Several issues to avoid:

Don't hide any junction box. It can't be under the insulation or inside a wall.
Wires should enter the junction box still in the outer insulation, and then you'll need several inches inside the junction box to make the connections. If the existing line doesn't have a lot of slack, then you won't have the space to do it.
Circuits and the associated wiring have a capacity that you cannot exceed. Doing so will trip the breaker in the best case, or cause a fire if the breaker is upgraded without changing the wiring.
Wires going into the wall need to be stapled to the center of the stud, so you're going to open up a wall eventually. Do not attempt to fish them down the wall and leave them hanging free.

Like ChrisF says, if you don't know what you're doing, you would be wise to call a professional.


What wire is needed for a 400 Amp service between the mast and the meter?

First off, the utility generally makes the hookups at the service masthead
The first order of business is a point of clarification.  According to what I have been able to find, your utility is conventional in that they make the final connection from the service drop to the service entrance conductors coming out of the weatherhead; the 18" tails are required so the linesperson can make those splices comfortably.
As to sizing...
This leaves us with mast and conduit sizing.  A 3" rigid (galvanized) conduit mast is generally considered adequate for a 400A service entrance, at least from the utility service requirements I have read, as physical strength is also a factor here, not just conduit fill (although a smaller conduit wouldn't work anyway, as you'll see below, due to the need to upsize the wires).
This brings us to wire sizing, which is a bit non-intuitive as parallel wires still need to have their ampacities derated for fill as per NEC 310.15(B)(3)(a), but we also have to apply the 83% demand factor for residential services provided by 310.15(B)(7) point 1.  Furthermore, meter socket lugs aren't rated for 90°C, so we have to use the 75°C column instead.  This means your 4/0 is right out as two 4/0 wires in parallel can't even get us to 400A to begin with before we apply the derating.
So, we must upsize the wire.  While 250kcmil seems like an attractive next stop, and two 250kcmil wires in parallel can manage 410A on 75°C terminations, we have to take 20% off the top to account for the fact there are 6 wires in the conduit.  This puts us down at 328A for the parallel combination, just short of the 332A required by the 83% rule for a 400A nominal service entrance.
As a result, we find ourselves looking at 4 300kcmil Al XHHW-2 wires in the service entrance mast, 2 per leg, along with 2 250kcmil wires for the neutrals since the line neutral lug on your meter base can't take anything larger.  These give us a healthy 368A after the derate is applied, which is more than sufficient to meet our 332A requirement.  (Were this not a residential service, you'd have to provide for the full 400A nominal requirement, which'd require another size bump to paralleled 350kcmil conductors.)
You are correct that 600kcmil is the right size for using a single wire per leg for the service entrance, though -- this gives you 340A at 75°C, just enough to meet our 332A requirement.  Furthermore, it is about $0.50/ft cheaper at the time of this writing than the parallel conductors, and also takes up slightly less conduit area, albeit not enough to actually matter.  However, the larger conductors can be more difficult to pull through the conduit, which may be an issue, although the reduced surface area compared to the paralleled conductors means you have less chance of skinning the wire, all the same.


Is it common for professional drywallers to tape narrow corners, but not mud over the tape if it's going to be covered with moulding?

Personally I would not lose a lot of sleep over this.  The molding will probably cover it up.  If not have the contractor make the necessary adjustments.  Tape would still be needed for the seam that is above the door that we can't see in the pictures.  Do you feel that part of the seam was properly done?  There is also an indentation on the edge of wall board for the tape that might have been easier to fill with tape instead of just joint compound that shrinks and could crack.


What should I consider when buying a USB inspection camera?

You might call the local rental center and ask if they have something.  If you just need it once why buy?  An inspection camera is nice, but you might also be able to see what you need with a mirror.

Another idea might be to slide pipe insulation or split tubing over the pipes.  This can trap the leak and guide it to where you can see it.


Resin in softeners is typically only good for 10 years, and after that has to be rebedded (replaced).

1. Empty the old media from the tank

Turn off the water supply and relieve pressure on the softener (easy way is to manually cycle the valve to drain a couple times until you don't hear water moving anymore).

Disconnect the softener, and bring it outside. It is filled with water and quite heavy -- you might need two people. A hand cart is especially helpful. Be sure to grab the softener itself, and not the brine tank which sits off to the side (the part you put salt in).

My dad used to own a water treatment company, so I've done this many, many times. The way we used to do it was take a large plastic garbage bin, with a large bag in it, and basically just pick up the filter and dump it upside down quickly. The water in the tank would help get most of the media to come out, along with shaking it a bit (think along the lines of getting ketchup out of a glass bottle). Once all hte water is drained out, keep it upside down and use a garden hose to flush out the rest of the media and clean it out.

We used to then just take a screwdriver or knife and poke holes through the garbage bin and bag to let it drain, but of course this wrecks the bin (we had several of these, and they'd be good for hundreds of rebeds before falling apart). Be creative so you can drain the water and then dispose of the used media.

2. Prepare the tank

Install the stem back into the center of the tank. If the stem or distributor basket (intake on bottom of the stem) is damaged in any way, you'll want to replace it.

It's a very good idea to cover up the top of the stem with tape so nothing gets down inside (could jam in the filter head later, causing lots of problems).

3. Fill the tank with new media

Put some small pea gravel in the bottom, usually enough just to go an inch or so over the basket, but the manufacturer should have specific recommendations.

Next, install the resin. Again, the manufacturer should be able to list the specific type and quantity needed. If I recall correctly, it should fill up to a foot or so below the top of the tank.

4. Reinstall the tank

Bring tank back in the house, and hook it back up. It's a good idea at this point to check all o-rings too, and put silicone o-ring lubricant on them to prevent them from drying out and make it easier to reinstall.

Don't just turn the water on full-bore, or you risk stirring everything up inside. Instead, open a tap somewhere downstream (or set the filter to drain), and then slowly open the supply to let water trickle in. Once you see water coming out of the tap or going to drain, it's full and you can open it all the way and put the filter back into full service.


They're not intentionally left open. Masons apply mortar to the two faces of the block and typically there's a gap left in between. It would be difficult to get the joints completely full without massive waste in the form of squeeze-out.

You can fill them with about anything that meets your needs.


How thick of shims can I use to bring new wood floor up to tile height?

Either 'shim' up with subflooring that comes as thin as 1/8" or use self-leveling concrete. If you piecemeal the shimming then you're likely to get squeaks and other issues in your hardwood flooring


It is very hard to describe knife sharpening in text.  I'd recommend searching out a few Youtube videos for tips on technique.  That said, I'll add my 2 cents worth.  Everyone has a different idea of the "correct" way to sharpen a knife; below is just how I was taught.

What is the proper way to sharpen a knife with a stone like this?

If the knife is already sharp and you're touching up, start with one of the fine stones.  If not, start with the coarsest.  Work your way from coarser to finer.  Put some oil on the stone, put the edge of the knife on the stone at the angle you want (try to match the existing angle), then stroke the knife along the stone as if you're trying to remove a fine shaving of stone.  Pull the knife as you do it to sharpen the entire edge.

Do I need any other tools?

No.  A jig for keeping the sharpening angle can help, but most likely wouldn't be usable with a stone like this.

Do I need any protective equipment?

No, but be very wary of where your fingers are, and where the edge can go if you slip.  Keep your fingers out of that area.

Do I have to use some type of oil?

Yes, to carry away the swarf, or metal particles.  For cooking knives I use a vegetable oil.  Yes, veggie oil can go rancid, but cooking knives are used and washed often enough that it's not an issue.

Is it better to go fast, or slow?

Slow.  I like to take long strokes along the whole edge, concentrating on keeping my angle consistent.  I use about a 20 degree angle on kitchen knives.

Is the procedure different with a knife that has never been sharpened before?

Only that you would probably start on a coarser stone.

Do I have to do anything different if the blade has rust on it?

Remove the rust first with fine sandpaper.

How do I know when the knife is sharp?

There are many ways to test.  The old newspaper test, where you hold a piece of newsprint in one hand and cut it with the other is a good one.  You can try shaving your arm hair until you run out :)

But really, watch some videos and just practice.


Sweating or normal condensate is a byproduct of air conditioning. Dripping in the pan and will continue to do so until the humidity is 20-30 points lower then it will slow but continue to drip (that’s why there is a pan to catch the water or condensate)
Once the water is caught it can be pumped or piped out of the home.
If you have sweating on the outside of the unit you are lucky your pan catches it. Insulating that metal surface can reduce or even eliminate sheet metal sweating when sealed with insulation.
So sealing is a start but insulating the ductwork Will be needed because as long as there is cold metal in a high humid area it will sweat.
If you have a glass of ice water is it sweating? Your metal parts are the same.


Need a small compression rod for stabilizing my dryer

I would suggest that you get yourself some high density foam material similar to the type used for padding furniture cushions. You can get this material in various thicknesses so you would want to measure the gap from the sides of the dryer and the walls and purchase accordingly. One Example

The idea is to cut the high density padding into a square of say 1.5 or 2.0 feet on a side. Then squeeze that in between the wall and the dryer sides. You will want the material to be under some compression when it is installed. It may be necessary to insert two pads of different thicknesses on top of each other to get the needed space filled up with some compression.

This approach has some decided advantages as follows:

The foam material will act to muffle the sound coupled to the wall. Your idea with point contact will more likely couple sound right into the wall.
The foam pad extends out over a larger area of the dryer sides to provide stability and to reduce the drum head effect that metal appliance walls can create.
The pad spreads the compression load over a large surface of the wall to prevent wall damage. A point type of compression assembly would have to be positioned over a stud to ensure that it does not eventually break into the wall. This would be particularly an issue for the very common drywall material made of paper and plaster material. With the foam that load gets spread across a large area.


How do I remove drywall stuck between flooring and wall?

Keep it simple, use brute force.

I would just use a wide chisel and hammer to smash it up, then a large screwdriver or some such tool to scrape it out. Diagonal cutter or needlenose pliers would make short work of any nails encountered. Use a shop vac to then clean that slot.


How can I calculate the yield strength of steel tube?

Some physics.  Assuming the same material, length and loading, the bending strength is limited by the Second Moment of Inertia (I) of the cross sectional area.  The math is complex, and even given a calculator, it's a bit confusing.

Assuming a vertical loading, You can estimate the relative change in the I value by cubing the scale change. (This estimate is accurate only for solid rectangular beams)  This suggests that multiplying the vertical dimension by 1.5 would give a resulting increase in strength of 3.375 times.

If you're increasing the horizontal thickness, then you simply multiply by the scale.  So increasing thickness by 1.5 would result in a strength increase of 1.5

I ran some numbers in an I calculator, and assuming a 3mm thickness, I got a value 3 times higher for 1.5" than for 1" if loaded against the longer axis, which shows that the estimator is reasonable.

For a 3mm tube of one inch, I got values of .8 and 2.75 for 1.5".

All things being equal, a hollow square is better than a hollow circle, and a hollow rectangle is better than both -- if you load it in the right direction.


Does door jamb size make a difference in installation?

Yes. Set the door flush to the exterior. Google "jamb extension" for the rest. (Your jamb extensions will probably be 2", so likely to require ripping.)


Framing Advice - How to re-frame opening of non-load bearing wall

I think you need to trim the 2x4 studs in the opening and build a header over the whole new opening, like the header that was over the original doorway, which will extend across your new opening.

Something like this:

(hopefully you're better at it than I am with Photoshop...)

Taking care to attach to existing studs on the right side and adding a jack stud (doubling the stud) at the end.

Like this:

I also think that you'll have to do some work on the "knee wall" (half-wall) to make sure it's sturdy enough, too. I assume it's just 2x4s toenailed into the bottom plate and maybe a double stud on the end (left over from the door frame)? It's hard to know for sure since we can't see what's left.


Is it safe to use an extension ladder in the garage?

The distance the ladder base should be from the wall is 1/4 of the vertical height of the ladder contact point. The side load will be minimal. However with the ladder against the rafters it will be difficult to position the insulation and not have the ladder in the way.


Can I cover junction boxes in the attic with insulation?

Your best bet in this case is to contact the local inspector,  since this situation may be open to interpretation. The most fitting code states:

  National Electrical Code 2008

  ARTICLE 314 Outlet, Device, Pull, and Junction Boxes; Conduit Bodies; Fittings; and Handhole Enclosures

  314.29 Boxes, Conduit Bodies, and Handhole Enclosures to Be Accessible. Boxes, conduit bodies, and handhole enclosures shall be
  installed so that the wiring contained in them can be rendered
  accessible without removing any part of the building or, in
  underground circuits, without excavating sidewalks, paving, earth, or
  other substance that is to be used to establish the finished grade.

  Exception: Listed boxes and handhole enclosures shall be permitted where covered by gravel, light aggregate, or noncohesive
  granulated soil if their location is effectively identified and
  accessible for excavation.

  Article 100 Definitions

  Accessible (as applied to wiring methods). Capable of being removed or exposed without damaging the building structure or finish
  or not permanently closed in by the structure or finish of the
  building.

It may or may not be acceptable, depending on if the inspector considers insulation "part of the building".

If you do end up covering the boxes, it might be a nice idea to mark/flag them in some way. This way you; or any other future owner, will be able to locate them later if need be.


Advice on how to remove a faucet cartridge

It looks like what we call a "Delex" cartridge; the original version was manufactured by Delta but there are knock-offs using the design now.

Once the retainer nut has been removed, that cartridge is just pressed in; keep yanking directly upward and it will come loose. I sometimes craft a "pull handle" with a flat piece of steel (like a crossbar for a light fixture) and screw that to the stem using the handle screw, giving me something to pull on with both hands.

Don't make the mistake of just swapping out the cartridge; the actual seal washer is below, with a spring under it.


If the pipe itself is in good enough shape, you could just use a compression cleanout plug (sometimes called a mechanical cleanout plug) or a pressure testing plug:

There are quite a few different styles of these, but almost all of them work by compressing and expanding a rubber gasket inside the pipe. 2.5" might be hard to find at the big box stores, but they are available numerous places online. The main consideration would be finding one that would seat deep enough into the pipe that it would be beyond the notches for the old cap.


How can I attach normal framed walls in between concrete columns?

Your solution is fine.  I have seen that done a lot.  Although, steel studs are used more often in this type of setting.  I think I would use a Hilti gun instead of concrete anchors, this will save time, money and be more secure just  because you can have more nails than you could ever put anchors.


Things vary according to location but around here, you contact the local power company and request a temporary pole and disconnection of your current service.
Once that is done, you can complete your demolition and remodeling but the power company is going to expect to find a finished meter box that they can run the service drop lines to and then install and seal a meter for your new installation.  Then they will remove the temporary pole.
You are not authorized to mess with the always energized service drop wires on the company's side of the meter.


How to find a motion sensing light switch that turns lights on AND off when motion is detected?

Put the sensor in the space you are trying to light, and suddenly this "common need" becomes "not a need at all" which is why you can't find them, since that's how it's done, when done conventionally.

Either move the switch into the room or get a remote sensor switch and put the sensor in the room.


need help installing bathroom solid surface countertop that does not sit flush on vanity

In my limited experience, the top is commonly adhered with either silicone caulk, or hot glue, neither of which care much about grooves (they will fill them where they happen to meet the glueline.)

Typically make some sort of witness marks as you where you want the top, remove it, glue or caulk on the top of the vanity, set the top in place following the witness marks, let it cool or cure depending which type of adhesive was used.


Figure 1. (a) 3-wire circuit. (b) 2-wire circuit.

You need a 3-way (as in "positions"), 2-pole, centre-off, switch for each blind. ( Note that "3-way switch" in North America means a two-way changeover switch as used in stairs lighting.)
Figure 1a shows how to wire it with three wires assuming the end-of-travel switches are installed in the motor mechanism. As drawn, the motor will run until the open position is reached. The OPEN limit-switch will open and stop the motor. By switching SW1 the motor will run until the CLOSED switch opens upon which the motor will stop.
Figure 1b shows how to reduce wiring to 2-wire by the addition of a pair of diodes. As shown, current will flow through D1 until OPEN opens, as before. When SW3 is reversed current can flow through the CLOSED switch and D2.

We have no idea if the switches or diodes are in your blinds mechanism at this time.


Thanks to everyone and particularly to ThreePhaseEel for his suggestion that helped me diagnose the issue.
My non-contact voltage detector picks up current within about 18 inches of the fan housing, even while the fan is turned off. The other two bathrooms have the same model fan assembly installed, but the voltage detector doesn't read anything from just beneath their housings, even when they are turned on!
Clearly something is not wired correctly in the bathroom where I got shocked, and the shock which I received when I touched the air compressor must have originated from the fan assembly/housing, which is apparently hot all the time.
I didn't get shocked when I removed the cover from the fan assembly, or when I touched the inside of the housing while inspecting it, but maybe that's because I was standing on a fiberglass ladder. My guess is that I got a shock when my body formed a circuit between the electrified housing and the air compressor (which was plugged into the wall and thus able to continue the circuit), and I just happened to be feeling the shocks on the air compressor side even though the current was coming from the fan housing.
Update:
The cables on my multimeter are not long enough to reach from the fan housing to a safe grounding source, but my uncle brought over a wired voltage tester with long cables. We put one probe into the ground port of the bathroom outlet, and touched the other probe to the fan housing. The tester immediately beeped, verifying that the housing is hot.
Update 2: Final diagnosis of the disastrous wiring

The fan (which is a 1500W combo unit with a heater and dome light) was on the same 15-amp circuit as all of the ceiling lights in that half of the house. I don't know how it never tripped the circuit breaker.
The vanity lights were on their own 15-amp circuit. Obviously whoever originally did the wiring mixed up the two, as the fan should have been on its own circuit.
The fan housing has a grounding wire, but the grounding wire was not connected on either end.
The fan housing was hot because the wiring to the vanity lights was frayed at the junction box, which is attached to the same metal framework as the fan housing.


The shims come ready made at lumber and big box stores or if you have one you can make them using a miter box and a 2X10 or the like.
My miterbox is an old Hitachi slide compound. It can cut a piece of material about 12" wide allthe way through. When I need to make shims I cut off scrap 2X10 or 2X8 blocks about 12" long. Turn the blocks 90 degree so the end cut is up against the fence and set my blade at .5 degree. I cut the edge to start one side, now you have a block that is slightly narrower on one side than the other. Then flip the block so the edge that was facing me is now up against the fence. I move the block so the blade is at the edge of the cut that was made first, but I line it up at the block that has the most narrow side, so when I cut the block again, the shim is made. I can be but not necessarily sharp on one end and about 1/4-3/8" thick on the other.

Keep flipping the block until the part you hold onto get too small, and start with another block. Needless to say you must be mindful of what is going on, too close and you could lose something.


I am not quite sure just what you are trying to do but from the picture you posted, the fitting on the top is a standard fitting for utilizing 1/4" OD plastic tubing and the bottom fitting is a standard 1/4" OD compression fitting. To use the top fitting with plastic tubing you cut the end of the tubing with a sharp object for a clean cut. Then, you slip the compression nut onto the tubing, then the 1/4" OD compression furrel. Next you push that small brass sleeve into the end of the tubing. Place the now adapted plastic tubing into that compression fitting (union) and tighten the compression nut. That small sleeve gives the plastic tubing strength to allow the compression nut to seal between the plastic and the nut. By the way, do not use the bulk type tubing, only use the tubing sold as ice maker tubing. That other stuff can break and cause water damage as I found out the hard way.


Just buy a little tub of joint compound, or spackling and cover up the areas.  You will have to paint it as well.  If it is a hole then get a small piece of drywall slightly bigger than the hole but where you can still get it inside (you may have to cut it bigger).  Drill a hole in the middle to fit a piece of string in it.  This will help you to hold it to the wall.  Use joint compound on the edges like glue.  When it dries, fill the void with more joint compound.  I've repaired many fist-size holes from when I was a teenager.


Connecting to small clock battery terminals

I would go to the store and purchase a wood dowel that is the same diameter as the AG13 battery. Then you can craft up a small pellet that has some small holes drilled at appropriate places and angles to insert small wires from your wire harness. The best termination of the wires would be to acquire some copper tape that has conductive adhesive and apply a couple of small pieces to the dowel side and face to mate with the contacts in the clock.

Do note that the wood dowel piece does not need to be as thin as the AG13 battery. It could be longer and even protrude some out from the back of the clock.

If you do not feel so much up to the task of DIY craftsmanship then I would suggest that you can just solder your wires directly to the contacts. This type of clock module is not so precious that you need to find a non-destructive manner to connect the wires.


Dried expanding foam on floorboards, how can I remove it?

I'd try scraping before sanding, using a razor blade scraper or a furniture scraper -- a slightly more targeted tool.


Hit wire on concrete wall while drilling a hole - problem?

You can't just leave damaged wires in the wall.  The circuit might seem to work for now, but when a higher load is placed on it or anything moves the wires just a little bit, they can arc, short out against the conduit and melt/burn/damage other nearby wires.  This could happen years down the road, or the next time you plug something in.

I mentioned conduit, because in a concrete wall, the wires are going to be running in some.  This should make repair easier since the damaged wire can be pulled out and replaced.  You will want to make a larger hole in the wall to inspect your damage and fix any sharp edges that would damage new wire or prevent you from pulling new wire in the first place.

Also, circuit breakers will trip when the wire is shorted completely, but some arcing and burning can happen at a low enough current that the breaker won't trip immediately.  You can't rely on a breaker when dealing with physically damaged wires.


Travertine can have many impurities, and being a sedimentary rock, could have a nugget of softer material.

In any case, use a stiff nylon brush and remove the chalky area.

Rinse the area and note if water absorbs in the nugget area..
If so, good; grout and/or sealer will attach securely.

I would recommend a bit of matching grout in the divot, followed by a penetrating stone sealer.(I prefer Miracle products, but others are fine).


Mounting Ethernet wall-plate in a solid wall

Nothing easier.  Install any sort of electrical 1-gang junction box on the surface of the wall.  Remove a knockout from the back of the box, and line it up so the wire comes through the middle of it.

The cover plate you linked is designed to fit to a 1-gang box.

I would go for either a $1 handy-box, or a Wiremold surface conduit box, depending on the aesthetic you want.


Why is electric heat capacity calculated using floor area instead of space volume?

Floor area is used for two reasons:

The temperature of a room results from a balance between the rate at which heat enters and the rate at which it's lost through the walls.  The rate of loss, in turn, is proportional to the surface area of the walls, floor, and ceiling, which, for a normal-shaped building, is roughly in proportion to the floor area.
Floor area is easier to measure.


AC minisplit (two condenser ((2x 24k) vs one condenser_48K with two branch boxes)

If you locate two mini-split condensers so close together that the hot air from one unit can drift into the other unit when the wind blows from a certain direction, that will reduce the efficiency. It would be better to separate the two condensers so hot air from one can dissipate before it reaches the other unit.
Also, try to locate condensers on the side of the house that is shady and cooler in the afternoon.


Does the metal receptacle box for 6-30 NEMA need to be grounded?

Yes, ground the box

Ground the box as you would for any other metal box -- with a ground pigtail that matches the gauge of the ground wires inside.


What's the best method and product to use for patching cracks in plaster walls?

I don't own a house with plaster so please take this advice with a grain of salt...

As you pointed out, the cracks usually appear due to settling.  As a result, you ideally want your repair technique to be resilient against future movement. As far as I know, there are 2 main ways of doing this:

Method #1: For smaller cracks, fill them in with painter's caulk (latex caulk).  Because it's a latex compound, it will (supposedly) expand and contract with the crack. It also makes cleanup a breeze.

Method #2: Use a joint compound specifically made for plaster work, tape over the crack, and apply additional swipes with larger blades to smooth the look.  The technique is described here: http://www.askthebuilder.com/B38_Plaster_Repair_-_Cracks.shtml (the author suggests drywall compound but as Niall pointed out, it's better to use other compounds).

-M


How can I fix a wall-mounted toilet that keeps running?

We had a similar problem with our Duravit toilet.  We followed the instructions above, and after pulling out both the intake water controller portion, as well as the flush control, he didn't find any calcium build-up: just some rust stains.   As a final check, my husband reached down into the toilet tank and felt something stuck in the bottom stopper valve. He felt what he thought was a broken piece of rubber, and after tugging on it with some force, he pulled the foreign object out in his hand from the access hole in the wall, and found a perfectly intact, but dead scorpion]2  It must have died just that morning when the toilet started running. Luckily he wasn't stung.


What could be causing this leaky evaporator problem?

The condensate collection works by allowing the water to run down along the fins and collect in pans on either side of the 'A'. Upflow systems work a bit better because the air flow supplements the water's tendency to adhere to the fins, whereas downflow systems tend to encourage release. Typically, even downflow systems collect most of the condensate. One problem that can occur is dirt collects on the fins, causing the water's surface tension to break. Surface tension is what causes the water to run down along the fins instead of straight down.

Another problem, which is probably what you are seeing here, though the others may be contributory factors, is simply just too much humidity. With high humidity, so much water develops of the fins that there is too much mass to be supported by surface tension and the water simply drops straight down instead of running along the fins.

So part of the solution may be to mitigate the contributing factors. If you can cool with a lower air flow, that will help. Change filters frequently, which it sounds like you are doing. Reduce the humidity in the house. This is easier said than done. But short of installing whole house dehumidifiers, be conscious of lifestyle habits that generate moisture and try to minimize it, such as always using exhaust fans when showering and cooking. Clean surfaces with liquids during the cooler parts of the day. Try not to breathe too much :)

I don't think you will fully mitigate the dripping with such measures. Moisture happens, and it will end up on the ductwork. You should consider fashioning the portion of the duct on which the water falls into a wide shallow funnel to collect stray condensate droplets and pipe it off somewhere where it can be safely removed.


How can I prevent my twin pocket doors from meeting too hard?

Take a look at latch on web page http://www.johnsonhardware.com/1521.htm , when the doors are closed they latch together with out locking.


What could cause a central A/C system to smell but only after central heating had been used?

Smells in AC systems are somewhat common.
When the heat is used the drip pans dry out and any gunkies (a professional term for growth in the drip pan).
When the AC is used the dormant gunkies get some moisture and come to life.
The moisture is normal when the AC is on.
Ways to reduce or eliminate this growth add condensate pan tablets or strips that kill the gunkies without stinking the house up, bleach will work diluted but it stinks.
My normal mold treatment is a no no (hydrogen peroxide) DO NOT use any acids as they will eat the galvanized treatment off the drip tray and etch the aluminum parts.
You really only need to use these during cooling seasons not during heating because when heating there is no moisture in the pan. The tablets, strips or whatever use the moisture to kill the active fungus in the gunkies.
The gunkies are dust with mold / fungus growing and they can build up and block the condensate drains,  produce bad odors and create health hazards like legionnaires (first found in commercial AC systems). Simple sanitizing tablets or strips prevent the growth and can be purchased at most home stores.


There are bare copper wires in the light box?

You have at least two non-metallic (NM) cables coming into that box. Each NM cable (and other types) must now have a ground wire. In the US, most of these cables have a bare copper ground wire. Sometimes you will see ground wires with green insulation, and occasionally on fixtures you will see a bare stranded wire with tinned (silver) coating.

At least one of those cables leads back to the main panel box which houses the main ground connection. The goal is to have every fixture and device (including any metal boxes) connected to ground. This is accomplished by attaching the all of the ground wires of the cables and devices at each downstream location together. This is totally correct.

These wires don't normally carry any current. Ground only would carry current if there were a failure of the other wires, and then it would serve as an emergency connection to carry the current literally to the ground rather than letting it shock a person or cause a fire. In most cases, this would trip a circuit breaker.

To be properly connected, most modern switches and fixtures should also have a ground wire. These might be bare or covered in green insulation. They also should be connected to the bare wires from the cable.

While attaching bare wires to screws is acceptable, it is generally not proper to put two wires under one screw. Usually several bare wires are connected with a wire nut or a push-in connector and an extra short wire (called a pigtail) is also bundled in. The pigtail's other end is then put under the screw of a device, switch, or box. An exception is when the wire is actually continuous, and the  wire under the screw is really just a loop rather than two separate wires (which may be your case).


Can I run NM-B inside EMT conduit for protection?

In full EMT installations, it would be very hard to pull romex through EMT.  Also, if you need to rewire or add additional wires, it would be near impossible to do without taking everything apart. It's definitely okay to do, in fact it's required to protect cable from damage.

2008 NEC - 334.15 Exposed Work says, "Cable shall be protected from physical damage where necessary by rigid metal conduit, intermediate metal conduit, electrical metallic tubing. . . ."  See also Can Romex (NM-B) be run through conduit?

An option, which may be appropriate for you, is you can run regular NM-B along the wall close to the ceiling, and come down to your box with EMT.  This way your cable is protected from physical damage where it's needed, but you don't need a full EMT installation.  They make clamps which secure NM cable to EMT ends.   You don't want to overfill your conduit, as heat build might be an issue.

In my experience wiring my house, in the end I found it was best to do a full EMT installation and run THHN though it.  It is frustrating that 500 feet of White/Black/Green 12 gauge THHN is not cheaper than 500 feet of 12/2 Romex.


Why does my kitchen sink smell when the washing machine is running, and what can I do about it?

One or both of these drains are improperly vented. There should be a pipe going up, shortly after each of the traps, to vent the plumbing to the roof. Often this is done inside the wall where you normally wouldn't see it. Without it, the flow of water going down the drain can build up pressure and push sewer gases past the trap and into your home.

The fix is to properly vent the drain, by either removing the blockage in the existing vent, correctly hooking the drain line to the existing vent, or installing a new vent either to the roof or with an air admittance valve.


What windows should be used to soundproof from traffic noise?

There are a number of companies that provide windows with high STC ratings. The series 7000 windows from http://www.silent-guard.com appear to have STC of 40 and above.  There are many other manufacturers that sell sound attenuating windows.

I believe you are correct that to get what you want you'll have to specify specific windows.  The way you describe the contract doesn't appear to be objective and measurable, and you really don't want to have to pay twice for windows.

You could also renegotiate the contract to specify STC rated windows of 40 or higher, however you might not get what you need then depending on how a given manufacturer rates their window.

Also, keep in mind that at higher STC levels the noise conduction through walls starts to become larger than the windows.  You may want to evaluate the siding/sheathing/insulation/wallboard plan to make sure that you don't put great windows in but still get significant low frequency road noise through the walls.


Does oil-based polyurethane have any residual toxicity past setting?

There are many discussions on this to be found. The bottom line is that any product has a parabolic curve of off-gassing over time. It reaches extremely small quantities after a few days of suitable curing conditions, and is almost at zero after a few weeks. Very few people would detect substantial odor after that.

I finished my office desktop with oil-based poly last fall. It was cured for long-term contact after about 2 days, but I could smell it for a few weeks. I don't notice it anymore a few months later. Your mileage may vary and depends largely on your personal definition of "toxicity".


How can I repeatedly cut the same pattern using a router?

I'd make a template in the shape of a square donut out of 1/2" plywood by using a table saw to cut out the square hole in the 1/2" plywood.  For example, if ...

i) the recess in the desktop needs to be 8"x12"

ii) the diameter of the base of the router is 6"

iii) the diameter of the router bit is 1/2"

... then I'd ...

1) start with a rectangular piece of plywood that measures 24"x28"

2) set the rip fence on the table saw to 5.25"

3) plunge cut on the table saw (advanced technique) along all four edges, but not all the way to the corners so as to leave the cutout solidly attached to the donut at all four corners.

4) make the final cuts in the corners with a jigsaw or handsaw or ...

At this point I ought to have a square donut template of the proper size.  If the router is not high-end, then I'd mark a spot on the top of the router's base that I'd always keep rubbing against the template (this is important for precision work).

To route out the recess in the desktop, I'd secure the plywood template to the desktop.  Then start excavating the recess at its center, progressing in an outward spiral until the final passes are done with the router's base bearing against plywood template.

Hope this helps.


I have building that is on a 20 amp breaker along with outside lighting

No!

The wire is (almost certainly) only rated for 20A.  If the breaker is tripping because more than 20A is flowing, then uprating the breaker will mean more than 20A flows through the wires, your wires heat up, and your house burns down.

(If the breaker is tripping because it's a GFCI breaker and there is a ground fault, then a 30A GFCI breaker will also trip, and a 30A non-GFCI breaker will ignoring a serious fault.  A fault which can kill you.)

tl;dr: You need to find the fault which is causing the breaker to trip and fix it.


Knock out the drywall around it until you can grab it with locking pliers. Either unscrew it or break it off (if it broke going in it may not want to come out any more cooperatively.) Spackle the hole and move whatever it is that caused you to drill it up or down a little bit so the new hole does not line up with the old one if the screw is broken off in place.


Can you use a 50 A GFI spa box on a 40 A circuit?

Yes, that’s totally fine.
Because the spa box is downline of a 40A breaker, it could be a 400A spa box for all it matters; it won’t be able to draw more than 40A.
I bet your car has 112 mph tires.  That doesn’t mean you have to actually drive 112 mph :)  The panel limit is just an absolute max, like a redline.  You can feed a 125A panel off a 60A breaker etc.
That’s why they don’t make 40A spa panels; there’s no need. 50A spa panels cover the necessity.


What fasteners to sister LVL to 2x6 joist?

Use the Simpson SDW22300 screw installed 6" on center alternating 1.5" from either edge, and starting 3.5" from the end.

This detail is for a built-up column, but it's the same idea.

SDW screw pattern

Doing it this way is overkill. It's probably possible to do something similar with 10d nails, but that's more than I know how to do.


How can i fix sweating Duct work in my unconditioned garage?

Air seal with air duct sealant (a gray goo that hardens after it's brushed on or applied with a putty knife), not duct tape, and insulate, preferably a LOT better than R8 (your heating/cooling cost is hugely affected by poorly insulated & leaky ducts in unconditioned space.)
You can reinforce the duct sealant by embedding fiberglass mesh drywall tape in it. I don't suggest using duct tape because it has a habit of falling off after a few years.


Can I connect an indoor water meter to water heater with PEX?

IMO I would use something more robust like copper, galvanized, or brass from the meter to the shut off if exposed at all.  Then use PEX after the shutoff.

Just know PEX is not designed to be left exposed to UV light like the sun or physical abuse of any kind.  If receives much of either, I would use another material or get it covered up.

On that note, we see PEX all the time on both sides of a shutoff and you  probably (not entirely sure of your circumstances) can use PEX from your meter to your shutoff without any problems.