A salt water chlorinator does not produce chlorine gas (it uses the salt in the water to produce hypochlorous acid and sodium hypochlorite: source). Moreover, the process takes place under water in an enclosed container. You therefore shouldn't have any fear of harmful gases from that process.

Furthermore, the smell that poolgoers usually associate with "chlorine" isn't actually due to chlorine but to chloramines (byproducts of chlorine sanitising organics in the pool) which indicates a lack of free chlorine in the water. Because salt water chlorinators can produce free chlorine continually, you don't usually get the "chlorine" smell with salt water pools.


Can I replace two light switches with a single light switch?

This explanation assumes you are trying to control both sets of lights at the same time and not independently.

If they are on the same circuit, having separate hot wires to each switch is really redundant. The return wires from the switches are not.

There is no problem ganging both lighting fixtures on the same switch so long as the switch is rated for the power the fixtures draw. Most modern dimmers are rated 150, 300, 600 or 1000 watts. You need to make sure that the two fixtures, added together, are somewhat lower than the switch rating. If not, your gonna need a bigger switch!

All you need to do is hook one of the hot lines to the switch and cap the other hot line with a wirenut.  Then pigtail both of the two switched lines (that return to the fixtures) to the switch output side. Do be sure to attach ground, for safety and to reduce the chance of random hum.

All of this assumes that the dimmers are suitable to the type of lighting (special dimmers are needed for many CFL and LED bulbs), that they are single pole (not three way), and there is no special feature requiring a neutral.

SUPPLEMENT

As Tester101 needs to regularly remind me, current code calls for a neutral wire at all switches. You have an extra wire in the switch box (the redundant hot) that could be converted to a neutral if you ever need it. You would need to switch it over at the fixture to the neutral white line, mark it at the fixture to show it is neutral (e.g., with white tape) and mark it at the switch box as neutral (also white tape).


That is a PIPE UNION.  It is needed where you are unable to screw the threads together normally.  If you look at the structure, you'll be stuck when you try to assemble the top without a union.

That is a PIPE FLANGE.  It's not usually used in plumbing per-se but is often used where iron pipes are used for other purposes such as what you are doing.


Can I connect the supply ground wire to a fixture's ground wire with a wire nut

Yes. What you propose is safe, code compliant, and good workmanship.
Electrical codes in most locations require that a ground fault wire be either bare (uninsulated), insulated in green, or insulated in green and yellow stripes.


If the footprint of the new deck fits over the patio, you should be fine with a freestanding floating deck. Precast post blocks like this can transition from the slab to the deck framing, and provide the all important gaps so the framing can dry out:

Consult locally for wind tie down requirements: you'll probably need to sink some anchors into the slab, and add cable restraints to the deck framing : any sort of roof will act as a sail.  Going freestanding greatly reduces headache and risk of attaching to the house.


What kind of treatment do I need to stain/paint this deck?

That is paint.   And that is paint with no primer applied.
That is good news for you as you don't like the color.   It is bad news for your deck, as it has probably logged a lot of water.
The easiest way to remove this is roll on some paint stripper and get a power washer going.   You are going to have to access how each board looks after you can see it better and replace anything showing signs of rotting.
Can you stain pressure treated wood (pine)?   Yeah... but you are going to have to try some things out and make sure you are happy.   The cheapo pressure treated big box lumber from experience does not hold stain great.
However you have an edge because you want it darker and a darker stain might hide the imperfections and hold better.   You are going to have to try some sample of stain and just hit small parts of your deck - I would do the decking or tops of railings to test.


Planning to switch to a tankless water heater

You cannot combine an exhaust vent for a tankless heater with other vents. For one thing there would be a possibility of the exhaust from the WH going the wrong way in the other vent. The WH must have a dedicated vent.

Also depending on the model the vent may have a requirement for a certain length of vertical run immediately adjacent to the heater before you have a horizontal run. (Tankless WHs with power vents may not have this requirement.)

It will be very costly to retrofit a new vent path for a tankless heater through multiple stories and out the roof. Reconsider your reluctance at venting out a side wall. This would almost certainly be much better, simpler and cheaper. A new roof penetration is an invitation to a roof leak because plumbers in general  don't properly flash a retrofit roof penetration. Ours leaks!

Even though the current location is not ideal it may be best to use the same location as the current a gas fired tank. Note that the tankless water heater draws a lot more gas when it is on (up to 4 or 5 times more) than a 40 gal or 50 gal gas tank. The gas supply line and the gas meter must be large enough to supply this amount.

Different models of tankless WH have different sizes and types of vent. It would be a pretty thick wall that would allow one of these vents to be inside a wall.

If the copper water supply piping is in good shape, there would be no reason to replace it with PEX. It may help to put foam insulation around the hot water line wherever you can.

Thirteen years ago we replaced our 40-gal tank with a minimal Bosch tankless WH because twice when our tanks failed they flooded our 1-story house on a slab. If your WH is in the basement, I doubt it is worth it to change to a tankless.

Tankless WHs require periodic descaling with vinegar and they do not supply the flow rate of hot water that most Americans are used to. If you are having a problem with running out of hot water for multiple simultaneous and sequential showering, the best solution is to install low flow shower heads and encourage shorter showers.


Can I install 2 30 amp twist lock receptacles in a 2 gang box on 1 circuit?

This keeps coming up: The question of whether you can put more than one receptacle on a 30A circuit.

All the receptacles must be 30A.   (NEC 210.2B3)

It's very surprising to find 30A plugs on machines that fall considerably short of 30A. Generally they use a 15A or 20A plug if they are able.

I'm not sure you can fit two of those connectors two abreast in a 2-gang box.  That's a mighty tight fit, and I'm concerned with the screws striking each other.

It'll be tight and awkward to grab, and depending on the plug, they might interfere. I'd go a double-gang bolted to a single-gang with a conduit nipple.

Big receptacles don't have 2 screws, so you'll need to pigtail them.  The extra wire count will mean you'll have a lot of box fill, in both the Code requirements and in the actual sense. You'll need a very deep box.


What does the citation mean?

The facts are that you need to apply the new codes inside the scope of new work, and the remodel qualifies as new work.  The areas of the house you are not touching should be grandfathered.  The section of the code you are citing did not mention that fact.  This is a common problem with citing random bits of code.

The code says you need AFCI protection in all those places.  However this is overridden by the fact that the other locations are grandfathered.  The area you are doing new work is not grandfathered and the requirement applies there.

New panel

You can replace your existing panel if you really want to.  Or if it is a dangerous FPE.  Or if it is an obsolete panel like Pushmatic where you won't be able to get AFCI breakers.

However, you can also install a subpanel.   You would need to move a number of circuits over from your existing panel to the new subpanel - enough to make space for a large double breaker, which will power the subpanel.

Now if you need 2 extra circuits and need to move 4 to make the space, you can get a 6 space panel.  However that means you'll be right back here again next time you add anything.   You could add a 12 space panel but again you are just kicking the can down the road.  This is where my colleagues recommend a 20 and I recommend a 40 space panel.  The cost is trivial compared to the cost of having this problem.   My first motive is to never have to deal with this again, ever, and my second motivation is to plan ahead so the subpanel can later become the new main panel, after you move circuits over, one at a time at your leisure.

Also beware of panels which say "50 circuit 30 space", those are only good for 30, because the double-density breakers are not available in the GFCI or AFCI that almost every circuit requires these days.

The subpanel can be next to the main panel (a good idea for a future switchover).  Or, if the kitchen is fairly far away from the main panel, it can be near (not in) the kitchen.  That will make all your circuit runs much shorter.

Everything related to the new panel work will lose grandfathering and need to meet current code.   This is one reason to do the subpanel instead of replacing the main panel; it avoids having to upgrade every circuit to new standard, almost all both AFCI and GFCI.

While we're on the subject of overbuilding...

Also, what sort of activities do you expect in the kitchen? Any chance someone might be, I don't know, just spitballing here... cooking?  Because these days, a lot of kitchens see not much, while others see quite a lot.  Those can be populated with coffeemakers, toasters, skillets, grills, sous vide, wafflers, you name it.  These heat-making appliances are typically sized at 1500W and cannot share a 20A circuit.  And your chef will probably want to use several at once when busy.  S/he will mightily appreciate it if your kitchen is populated with as many kitchen countertop circuits as you can bear to install. One circuit per receptacle is not excessive.   Crazies like me even go for one circuit per socket.  This is where a subpanel near the kitchen will be particularly useful, and that's the easy way to do it.


How to get stains completely out of carpet?

Place carpet in dumpster.

Install new carpet.

Or something other than carpet where you have been prone to dropping food on it - sheet vinyl or some other easily cleaned surface.

A carpet cleaning machine may or may not work on any given stain, thus, this is the only sure-fire way.


How can I find a leak in underground plumbing?

We did turn off the water last night and the power to the water pump and found that over a couple hours time we lost all the water in our reserve tank. Does this sound like a leak to you?

Maybe.  Was the reservoir tank cut off (like with a valve) from draining back down the well?  If there is a check valve, is it in good working order?  If not, it is hard to say whether the reservoir fed a leak or just emptied back into the well.

To more definitively indicate if well water is causing the observed ground water, turn off the pump, close all the water valves (to prevent water flowing out of the pump house) and wait.  Observe the ground water level every hour or two—maybe put in a stake or stick in the hole to better track it.  Does the water go down?  If so, a leak seems likely.

Leak detection

Doing a standard pipe pressure test would indicate quickly and conclusively identify whether there is a leak anywhere.  It requires containing the pipe under test by closing valves or disconnecting and capping pipe, adding a gauge or other measuring device, and pressurizing the pipe, perhaps with a bicycle tire pump—a gas pipe pressure testing gauge has an air valve for this purpose; I haven't seen anything directly comparable for water pipes.  Then just wait and watch.  The pressure should remain, dropping no more than 5% per hour.  (In my experience, temporary caps and a gauge for leak testing are the source of most pressure testing leaks.  Generously apply plumbers tape.)

Finding a leak

If a leak is detected, then there are several choices to fix it find it and fix it.  Which you choose depends on the specific situation, your budget, and your patience:

dig up all the pipe to inspect for leaks
abandon the existing pipe and install new
Sherlock Holmes

The first two are self-explanatory.  The third involves looking for clues.  Can you isolate part of the system—the hot water portion is an easy and obvious example—and see if leak continues?  Maybe there is another portion:  outdoor faucets, sprinkler system, barn, etc. which can be individually cut off from the main system.

A leak is most likely to develop at a pipe joint and the location of joints are reasonably predictable.  If the pipe is PVC for example, it usually comes in 10 foot lengths (at least in the U.S.—but if it is freezing where you are, probably you are south of the equator so some other length—3 m?—applies), so you only need dig a hole every pipe joint to check—at least with good luck.

Also consider any recent changes if it got worse:  Has a fence post been installed or did a tree fall?  Dig around there for to look for pipe.


well pump kicking on and off every few minutes

There's a leak, assuming the pressure is varying and the pressure switch is operating normally.

If you are not seeing a leak, the most likely one is in the check valve at the bottom of the well (though we don't have any information about the type of pump you have - on a submersible pump, that check valve is in the top of the pump itself.)

You might also have a leak in the pipe between the well and the house, or in the well itself.

Finally, you may be running water in the house without being aware that you are - water softeners with faulty valves have done this to me, and leaky toilets are another common cause. If you have a main shutoff valve after the pressure tank, you can shut that off for 10-30 minutes or so and see if the pump still runs every 5-10 minutes or not. If so, look to the well side - if not, look in/around the house.


Grounded hot or a short will trip the breaker. But a loose wire will not.

With the breaker off, check every receptacle in the circuit for a loose connection. If you find backstab connections move them to screws. Start with receptacle nearest the breaker, though sometimes the wiring is not done in the most obvious /logical path.


Ground a dryer converting to a 3-prong cord - manufacturer hardware missing

What you have done is correct but whether it is safe is another thing. If I had to do this at gunpoint, I would have used a Stranded piece of wire with eye connectors at each end. That would give a much more solid connection at both ends without a wire wrapped around a screw over a eye termination.

To test the connections with a multimeter I'd go from the middle terminal to each end terminal and look for 120V, then from the two end terminals and look for 240V.

You should really do this according to current code and leave the four wire plug and run your existing feed into a new box and add a four prong receptacle.


How can I install a TV mount to metal studs?

A few things to consider when mounting is the weight of the television and whether it is a flat mount or swivel.  If the TV is heavy or on a swivel mount the "right" way to do it would be to open the wall and use wood studs to build a good support.
Here's my thoughts on metal stud mounting, but my preferred method is below this:
If the TV is not too heavy, I've mounted to metal studs using toggle bolts.  3/16" if its on the lighter side, 1/4" if heavier.  The pilot hole for a 1/4" toggle bolt needs to be 5/8" so its important find
the center of the stud.  This means finding the location where it starts and ends and drilling as close to center as possible.  You can use a stud finder to mark the approximate edges and then use the smallest drill bit you have to drill inside the markings to confirm where the edge is.  Measure and mark the center.  When you drill, take it slow, and have a sharp bit that can drill metal.  After you drill through the drywall pull the bit out to clear the dust, then start drilling the stud with some pressure but not so much you bend it.  This might pop the other screws on the stud above and below the area you're drilling.  Let the drill do the work, once it catches the metal and punches through it might be rough because the drill bit edges will catch the stud and rattle it.  Then setup your anchor bolts on your mount and push them all through and let the frame hang before tightening.  You may have to fiddle with the bolts to make the backs flip up and down.
The other, and my preferred option if the wall is standard drywall and the tv/mount is not too heavy is to mount directly to the drywall using the name brand Snaptoggle Toggler bolts, they work great.  The exact weight tolerances are here: https://toggler.com/pdfs/SNAPTOGGLE%C2%AE-Heavy-Duty-Toggle-Bolts.pdf but I recommend erring on the side of caution.  Buy a couple extra because the snap off feature can sometimes be tricky to get a hang of.


How can I get the light cover off my fixture?

There are fixtures now that screw in like a bulb over an keyless socket or similar. Turn the whole thing gently and see if it unscrews.

For example

https://www.homedepot.com/p/Commercial-Electric-Lightbulb-Replacement-Fixture-7-in-Round-White-60-Watt-Equivalent-Integrated-LED-Flushmount-Bright-White-54483142/205890895


This would depend greatly on the slope of the yard on either side of the drain. A (properly sloped) french drain should divert water about 5 times the pipe diameter on either side(assuming slotted corrugated black pipe in sandy soil) which doesn't come anywhere close to the 50-100 feet you need, so you would need a way to feed the drain area. The easiest way would be to slope the surface toward the drain. Plastic sheet buried under the surface, gravel and sand can also help direct water.

But, as already pointed out - french drains need somewhere to let the water out, and also have to be sloped (at least 1/4" per foot) to be at all effective; there are places they don't work and another solution is required.

This is probably a situation where we can provide better suggestions with pictures or diagrams, and a stormwater expert in your area may have even better advice since they're familiar with the soil and conditions in your area.


What do I do with the ground wire in a smoke detector install?

That looks like a plastic box to me. If it is metal, code requires that the box be grounded. If all the external parts of the smoke detector are plastic then a ground is not required (the same is true with light fixtures).
I don’t usually cap bare grounds. I just tuck them in the box (the entire length is conductive, so I don’t see the point). If it makes you feel better, put a cap on it and tuck it in the box.


Killing mold IN drywall using Borax solution - what now?

NO this plan has no merit, spraying the borax water solution in a hole would only get some, if any of the mold and you would be guesting anyway. If your house was on fire would you drill holes in the walls and spray water at the holes and hope?
The only way to check for mold is to open up the wall and testing spots that look suspicious.(If you really think that there is mold, you will need to have on a mask, googles, gloves,and full suit when opening up the wall, just to be on the safe side.) If the test show black mold you need have a specialist get rid of it.
See number 2.
Your question leads me to believe that you think that the borax is not going to work, but to answer your question NO. If there is mold and you do not get it all out, it can come back. Mold needs to be removed and drywall replaced. Black mold need to be remove by a specialist, and then you can drywall.


I am going to say that this was a purpose-built/proprietary drain assembly that was designed for and supplied with your special sink.
I have never seen one like that, and I have seen many many sink drains, p.o. plugs, pop-up assemblies, strainers, etc.
There are a lot of specialty plumbing parts available though. Like this one that I found when I Googled "double basket strainer":


Draining 2 series connected water heaters?

Since you didn't say it, and it matters - first, shut off the power or fuel to both heaters, so they are not dry-fired, which will quickly destroy them. This is very important any time a water heater is not full of water.
To flush the second tank, if they are connected in series, consider the first tank as if it was a pipe.
So, shut off supply, open hot taps, drain both, turn on the supply to flush the first, close the drain on the first, let the first fill until it runs into the second, flush the second, close the drain on the second, fill until no more bubbles come out the hot taps, and only then turn the power or fuel back on.
Might want to check the anode rods while you are there.
Be alert to the possibility that malfunctioning thermostatic mixing valves (as on a shower) could route cold water back to the hot side.


How do you navigate an unfinished attic?

Since my attic requires maintenance on solar vents and a power vent in the end gable, I took 5/8" plywood, divided it into three lengthwise strips and put a catwalk down the center of the attic. As a prior answer notes, use a small rake to fluff the insulation back over to the proper depth when you're through.

This was after a few years of playing Tarzan, catching the truss uprights and gauging where the feet went. Then you get off by two inches in a partial slip (did I mention hanging onto the truss members?) and find yourself staring ceiling repairs in the face. The plywood's cheaper than figuring out how to replace a ceiling with heating cables embedded in its lower surface.


Can I connect all of my LED strips to a single power supply?

The power rating of the supply must be higher than the power rating of the load -- so based on the numbers, yes, this seems sensible.

However, the strip lights themselves will not support running that much current through them -- which means you can't just daisy-chain all the strips lights.

From https://www.pololu.com/product/2547:

The 60 LED 1 m strip drew 3.0 A and had a voltage drop of 0.6 V.
The 120 LED 2 m strip drew 4.7 A and had a voltage drop of 1.4 V.

The voltage drop means you'll have dimmer LEDs.. and at some point they'll stop working entirely. To get around this, you should provide power to each strip. You can interconnect the data lines, but separate power wires should be run to each segment. How long the segments are really depends on how much voltage drop you can tolerate (how dim the LEDs at the end get).

You can use a voltage drop calculator (Google it) to figure out the size of wire you should use for the distance and power draw -- but expect to probably run 18 or 16awg wire from your power supply to the segment.

It may also make sense to use multiple smaller power supplies (with shorter runs), depending on your distances, room layout, etc.


Multiple switched circuits in single exposed raceway with T-style conduit body to branch them

The discussion in the comments revealed that the "planned addition" as described is perfectly fine but that the only detail that really needed additional confirmation was the conduit fill calculations, specifically regarding derating.

Since I'm using a T-style conduit body to branch a raceway for two fixtures there is not room to have a code-compliant splice between the common junction box and the fixtures themselves. This then means that separate neutrals need to be pulled and that there will therefore be more than 3 conductors in the shared part of the raceway. I had initially read that derating didn't come into effect for small wires (#14 and #12) until a much higher number of conductors are involved, but it was a good exercise to truly confirm this.

The NEC requires derating for 3-or-more conductors in one raceway. My initial impression for #14 THHN was that it's rated to only 15 amps, which would then mean that any derating requirements could be an issue for this 15 amp branch circuit. Looking deeper tough it turns out that 15 amps is only the required overcurrnet protection for circuits with #14 wire (from NEC from 240.4(D)(4)) and that #14 THHN is actually rated slightly above 15 amps at low temperatures. In my case I needed to derate 80% (for 4-6 conductors), and for #14 THHN at low temps this worked out to 80% of 25 amps = 20 amps, which still appears quite fine for the existing 15 amp branch circuit that I'm working with. This handy online tool, and of course the appropriate tables from the NEC (from 310.15(B)(16)), confirmed this.

So it looks like this planned addition is fine as stated assuming a wire gauge <= #14.


Roof trusses left out in rain, are they still good?

I believe this article should give you some answers:

http://www.sbcmag.info/article/2012/truss-storage

In short, it all depends on how the trusses look after the time. The article says that they may be left out for a week max and then should be covered, but any time after that just comes down to what the current weather conditions have done to them.


Electric outlet both sides 2x4 interior wall

I'd use 4x4 boxes that are 1-1/2" deep with single gang raised mud rings.  These will give you plenty of room inside.

Feeding through the backs of the boxes with a nipple sounds easy but will turn out to be a pain.  Better to just feed bottom to bottom with a short romex jumper.


Installing chain link fence gate, need advice on terminating the existing fence top rail

What if you used a rail end fitting and cut the connecting lug off. File it smooth and your done...


Can I provide a secondary power source for my thermostat?

If there's an easy way to get from the basement to the main ceiling, then you could just run an entirely new cable for your thermostat. There's nothing that says you have to follow the existing path. Just abandon the old cable.

You could even take advantage of this to move the thermostat to a better location, if you were so inclined.


I would get two bits of wood or stiff card twice the length of the hole but less than the width of the hole.

Put a screw in each piece of wood, close to the middle.

Make sure the reverse side of the hole is flat and apply a strong glue to the back of the hole and the face of the bits of wood.

slide the bits of wood into the hole - one at a time - and position.

Then with a bar and two blocks use some string to keep the wood in position by tying the screws to the bar.

Once dry,  fill, sand and re-finish as necessary.

Edit based on Jimmy's comment:
A variation that will be quicker, if you don't have time for the glue to dry (or to avoid glue at all), is to run screws through the wall and into the wood/card backer, adjacent to the hole, to secure the wood/card backer in place, driving the screws flush with the wall surface. Patch the hole and over the screws at the same time.


Fragile paperback on cellar ceiling batts

If the room above is warm and the cellar is cold, the batts were installed upside down if the paper face is towards the cold (cellar) side. The batts mostly fall from being full of condensation (water) when in that orientation. In any case batts should have more support on a ceiling than just the backing, whether that be wooden laths or sheetrock.

Replace, possibly with some other type of insulation. If using a vapor barrier (which the paper face is) put it towards the warm side. If in a climate where warm side is hard to figure out (heat .vs. AC roughly equal), consider cellulose, which can function well without a vapor barrier.


Where can I find LED indoor floodlights?

Most of the major lighting manufacturers are starting to produce LED spots and floods for can lighting - the only downside is they're not cheap.  I've been seeing them at various home improvement centers for 60-100 dollars a bulb depending on the type and wattage.

Sylvania LED flood @ Home Depot


Should I mop or sanitize subfloor prior to flooring install?

You should not mop, and you should not worry about it. The entirety of your subfloor is organic. Mopping will only create an actual problem--moisture soaked into your subfloor.
If you saw what carpet and other flooring typically goes over after a new build or remodel you'd realize that your concerns are unfounded. Vacuum well to prevent dust creep later and carry on.


Why would an LED stop flickering when connected in series with an incandescent?

It's the dimmer.  Dimmers and some electronic control circuitry need a minimum current to function.  Get a better dimmer module with a lower threshold, or one that dimms differently.  (PWM vs. resistive)  Or remove the dimmer from the circuit all together.


Why is my furnace filter alarmingly clean?

The thin fiberglass filters (usually blue in color) are referred to as "rock catchers" by some of my fellow construction friends. They don't do much to catch dust, but they'll stop anything large from damaging the blower. It's entirely possible that it was changed before you moved in and just hasn't had enough time to catch the little dust that it will catch.

If you really want to filter the air, you'll want to upgrade this to the pleated filters. Just remember that these do require changing on a more regular basis.

The other possibility is that you may have filters at your return vents doing a majority of the air filtering, and the filter at the blower is simply redundant.


Recurring banging in water pipes, cured by draining system

It's called "water hammer", and it's caused by the physical momentum of the water in the pipes being dissipated when the flow stops suddenly.

By draining the system, you're creating an air bubble somewhere in your plumbing that provides a cushion for the momentum, eliminating the banging, but this bubble is leaking away somehow, which causes the banging to resume.

A permanent cure would be to connect the bottom end of a vertical pipe that's a few feet long to a point near the service entrance in your home. Make sure the pipe is full of air and cap off the top end permanently. This will provide a permanent air bubble that should eliminate the banging for good.


Most nail guns come with rubber bumpers or you can get them from the manufacturer. You can also use a piece of cardboard over the trim and move it along as you go.


Frayed duct vent - can it still be used?

You may not WANT to, but in some decades of dealing with that junk, my approach now when I come cross the junk is to replace it with solid metal pipe and solid metal joints, and be done with it. So that's what I'd strongly suggest doing, like it or not. it's low quality, reduces airflow, and is generally horrid.

As for re-using it, which I recommend against - wrap a strip of duct tape around it past any damage to make a nice straight guideline for cutting, and cut along it. Use a nice sharp set of aircraft snips. Cut, do not tear.

If then too short, add a coupling or use some solid vent pipe to make up the difference.


Will craftsman trim saw make straight cuts in 2x4?

It is unlikely the saw will cut through in a single pass. This will require flipping the board over to cut the 10% that wasn't cut the first time. The straightest cut will require the use of a saw guide. A simple quick square would be sufficient. Doing a second cut will reduce accuracy as the guide will have to be repositioned. If you are making a cut on a single board the saw you have may work. If you are cutting a lot of 2x4s the saw will quickly use up the batteries. You will need two sets to be productive. Even with two sets you will likely use up the available batteries faster than they will recharge.


Does NEC require a separate circuit for a whole house fan?

I don't believe the fan mfr will call for a dedicated circuit but you may want to contact them to be sure. More than likely, they'll defer to local codes so also check with your local inspector.  As with any other device, consider the other loads on that circuit, and which ones could be operating at the same time, to ensure you don't overload the circuit.

Anecdotally... My own house fan is on the same circuit with my dining room & hallway.  In normal use, I'll have up to 11 led lights (154 Watts, about 1.5 Amps) and the 1/3 hp fan (6.7 Amps published, unknown actual) running and can add a vacuum cleaner with no problem on a 20 A circuit.

Fan specifics... The install instructions for a Dayton 1LXN7, 1LXN8, 2EAX4, and 2EAX5 don't say anything about a dedicated circuit. Their manual just says...
"Install the fan control(s) in the desired location and wire according to the appropriate wiring diagram (following applicable NEC and local codes).  Connect power to motor and 2-speed switch with timer using approved wiring methods."

The instructions for an Attic Cool/Ventamatic CX242DDWT, CX302DDWT, CX24BD2SPD, CX30BD2SPD, CX36BD2SPD, CX242DDWTHUB, CX302DDWTHUB, CX24BDM-2SPDHUB, CX30BD-2SPDHUB, and CX36BD2SPDHUB also don't mention a dedicated circuit...
"Note All wiring supplies and installations must meet or exceed the requirements of local electrical and fire codes.  Wire to 120 Volt, 60 Hz circuit only, using 14-3 two-conductor wiring with ground." ... "Install included switches in a double gang UL listed wiring box, in a wall close to the fan."


Can a condo interior room walls have steel studs that are paper thin?

Even though you found the stud with your stud finder, you may have missed it. Even steel studs will offer a bit of resistance to drilling, and you should see some metal filings or twists following the bit out of the wall. You may have to try again with a very small bit 3/4 inch one way or the other to find the stud. Use your stud finder to give yourself a better idea what side of the original hole you should try.  Of course, you can use the hole you already drilled by inserting a drywall anchor rated for the load you want to attach. I prefer the corkscrew type anchors to the expansion type.

There is a difference between the interior private walls and the common wall in condos. Common walls are always thicker, usually thicker sheetrock or two layers of 1/2 inch rock. This is for a longer fire time rating and soundproofing between units.


Term to describe two circuits run through one /3 cable

From Wikipedia

Split phase shared neutral (North American Wiring)
In split phase house wiring, for example, a duplex receptacle in a
kitchen is typically connected with a cable that has three conductors,
in addition to ground. The three conductors are usually colored red,
black, and white. The white serves as a common neutral, while the red
and black each feed, separately, the top and bottom hot sides of the
receptacle. Typically such receptacles are supplied from a ganged
breaker, i.e. a breaker in which the handles are tied together for a
common trip, so that if one kitchen appliance malfunctions and pops
the breaker, the other side of the duplex receptacle will be shut off
as well. This is called a multiwire circuit.

Notes:
These types of circuits must use a double pole circuit breaker

While the NEC recognizes this configuration, there is open debate as to weather or not this is a safe practice. For more information see Understanding the Dangers of Multiwire Branch Circuits
EDIT
Multiwire circuits for 3 and 4-way switches
Switch legs, also called travelers must now be in a different color to be easily identified.  A few years ago the white wire could be used as a traveler but code changed that to lessen the confusion of identifying the traveler.  Now instead of running a piece of 14/2W/GRD or 12/2W/GRD for 3-way you have to use 14/3W/GRD or 12/3W/GRD.  Same goes for 4 Way's also.


What length of finishing nail should I use?

Well, you want enough length that there is sufficient nail in the stud to hold the trim on. The drywall is 1/2" thick, so if your trim is 1/2" thick, that would only leave you 1/2" in the stud, which is not enough. So I would suggest 2" nails for what you are doing.


Instead of changing the size of the opening, use a pair of 24" doors in the "bypass door" configuration. They'll overlap 4" when closed and you'll have a 20" opening when they're open.

If you want to increase the 20" opening, you can cut the doors to make them narrower and this will still be less work than changing the size of the doorway. Even garbage MDF doors can be narrowed almost an inch on each side, especially if you're not attaching hinges or real doorknobs.


Breaker --> light switch (inside) --> GFCI outlet (outside) --> 3 outlets / 2 fans

It is either the GFCI outlet itself (doubtful, because you replaced it) or one of the 3 outlets or 2 fans. "10 minutes or so" isn't the greatest for troubleshooting, but not too bad. Your choices for troubleshooting are "one at a time" or "binary". I would go for "binary" if you can. This is also "divide and conquer".

Find an (approximate) midpoint if there is a chain from GFCI to the 3 outlets and 2 fans, and disconnect the wires there and see if the problem still occurs. If it does, then you know which 1/2 has the problem (unless there is more than one problem!) and can divide further.

or

Disconnect (and cap for safety with wire nuts) wires going to 1/2 the devices and see if the problem still occurs. If it does, then you know which 1/2 has the problem (unless there is more than one problem!) and can divide further.

Which method will be easier depends on whether the devices are in more of a "chain" or a "star" configuration.


How can I remove excess commercial flooring tile adhesive?

Does the container for the adhesive suggest anything for cleanup? Maybe mineral spirits or acetone? Be careful with those on your tiles though. Maybe "goof off" would work.


How should I connect two beams to a post at a corner?

Beams typically rest on their posts or trimmer studs. This case is no different, really, and there's no rule that says you have to have a chunk of post running up the height of the beams. I'd miter the beams at a 45 degree angle so that each rests on half the post. Screw them together well and toenail them into the post. It'll look something like this:

8 feet is a typical room height (92-5/8" precut studs with 3 two-by plates), and that's what's normally used for porches as well. Your situation may call for something else, though. It depends on may things.


How to calculate the requirements of a concrete slab?

Assuming your containers are 10’ wide x 40’ long and weigh 15 tons, that creates a bearing load of:

30,000 lbs. / 10’ x 40’ = 75 lbs. per square foot (DEAD LOAD).

Add 50 lbs. per square foot LIVE LOAD (40 is minimum Code requirement for residential construction).

So, TOTAL LOAD is 75 + 50 = 125 lbs. per square foot.

A 4” concrete slab can easily support 125 lbs. per square foot without rebar, but you’ll need “control joints” or the slab will crack. OR, you can add reinforcing steel. This reinforcing steel is called “temperature steel” and is not used for spanning soft spots, etc. I’d use #4 rebar at 12” on center each way in a 4” slab. (I don’t like wire mesh.) I’d also try to keep the slab as “square” as possible. No jogs, etc., because it will crack at the jog.

However, if the containers are going to be used as “habitable space”, you’ll need to install perimeter footings down below the frost line. Depending where you live, the frost line can be anywhere from 12” down to 48”...or deeper if you’re at the North Pole.

Yes, concrete slabs are usually installed on moisture barriers (to keep ground water from coming up through the slab) and on a gravel base (to even soft spots out which cause differential settlement). The size, type and depth of gravel will depend on your location.

If you’re located on a hillside, (you say you have to level the site,) make sure ground water is diverted around your site.

If your soil is mush, like where I live, you can’t use this type of construction (slab on-grade construction). You’ll need to install piers or piling and design a “structural” slab to span from pier to pier.


Do you run a conduit under or over concrete wrap in the basement?

On the inside--you don't want to mess with the wrap. By inside I mean close to your bench, not under the wrap. I thought I should expand under the wrap is a usually damp area that is somewhat corrosive I think of EMT for basements but messing with this barrier is not a good idea.


Why a SPDT momentary instead of a SPST momentary?

This is something of an opinion question - a reverse-engineering "why'd they suggest this?" question, but I'll take a swing.
In Leviton's low voltage catalog there are SPST and SPDT momentary switches in the Decora style. Both have center-off. It's easy to guess how the SPDT style works. Think about the implication for SPST with center-off: probably pushing one end of the switch causes a connection while pressing the other end does nothing.
A schematic diagram of the switch was not easily located in Leviton's literature, but based on outward differences between SPST and SPDT models, I expect the one-screw side is the common terminal and the two-screw side has both of the NO terminals. Tying those two NO terminals together does simplify the SPDT switch to an SPST function -- it's different from the SPST switch, though, because pressing either end of the switch activates the output.
The HRV vendor likely recommended the center-off SPDT switch to avoid the possibility that the user might "do it wrong" by pressing the wrong end of the SPST-type switch, likely resulting in a customer support call or worse.


Replacing receptacles protected by one GFCI outlet

Trouble shooting is about isolation of a problem. With that in mind and using safe procedures (never try and connect or disconnect while the breaker is on) you need to start at the GFCI and work your way down.

First disconnect all of the replaced receptacles and check the GFCI. This may be a rare occasion were the GFCI went bad. If it does work then connect each receptacle down stream until the GFCI trips and will not reset. Now we have an isolated problem and we need to figure out what is wrong with that particular device.

Once we have identified that problem proceed right on down the line one at a time until the circuit is complete and in working order.

I know this doesn't give you an exact answer to your problem but you can now narrow down the problem(s) and if the problem is not obvious then stack exchange can give you a more specific answer to your problem.

Hope this helps.


My roommate accidentally(?) left the stove on. Should I be concerned?

The only risk is the obvious damage to the pan, and the risk of whatever was in the pan catching fire and creating a lot of smoke, or possibly igniting surrounding materials.  If they meant you harm, they would have left the burner on without lighting it.


Is there at least room for a hammer drill that would allow you to drill smallish holes in the concrete, and then use stone-splitting wedges to break it up?

This would work if it's pure masonry, but not if there's any steel rebar in the concrete.

If it's reinforced (do you see any steel ends in the cut surface in the attic?), then I can't think of any easy way to get rid of it. A diamond saw would be slow, noisy and messy. Probably time to call a professional for advice.


What causes water pipes to shake violently with no known catalyst?

Water hammer happens when you abruptly close a valve.  Water has mass.  Once you get it moving toward the valve, if you slam the valve shut, the water is still moving. It slams into the closed valve and bounces -- water cannot compress.  Where can that ultimately go in a house where all the pipes are 100% full of water and all valves closed?  Back out to the street.  The energy is dissipated into the piping system and adjacent houses.

These last two words might just answer your question.

However, if you have anything that draws water automatically (and right on cue, as I typed this, my refrigerator dumped and refilled the ice tray), then that could be a source of internal water hammer. Machine valves are particularly notorious for closing very hard.

So your ultimate pressure damper is the rest of the city.  But check valves are starting to appear that permit flow only one way, and these may even be part of water meters now.  Needless to say, fitting a check valve makes water hammer much worse.

The conventional way to arrest water hammer (besides making sure all pipes are firmly anchored) is creating an air space intentionally in the piping. Water is not compressible. Air is very easily compressed.  Now, the water expands by compressing the air slightly, and that dissipates the energy.  It's a very simple fix, easily done by extending a pipe in a (at least slightly) upward direction and capping it off, creating an air space within.

Also, they actually make fat pipes or tanks designed to do this same thing. In the tanks, the air isn't "free" but is inside a "balloon" or diaphragm, so the water contacts the balloon instead of the air.

I suspect your problem arose because these intentional air spaces somehow became 100% full of water. It is certainly possible for air to effervesce into water. (exactly the problem the tank balloons are designed to avoid.)  By fully draining the system, you removed the water and allowed those spaces to refill with air.


Upgrade Electric Service from 100A to 200A

Spaces vs Circuits

First let's explain the 8/16 thing, or "8 spaces but 16 circuits".  At some point, panel manufacturers developed what I (alone) call a "double-stuff" breaker, which crams 2 breakers into a single space.  This is intended to solve crowding problems in too-small panels.

 photo source: Home Depot

Relying on these, marketing called their boxes 2X-circuit (X-space).  Around 2014 they mysteriously stopped doing that.  Recent NEC changes required AFCI or GFCI breakers on damn near every circuit...  AFCI and GFCI are not made in double-stuff breakers.

Your 16/8 service panel is a legacy of that bad labeling.  You have an 8-space panel, intended to replace an 8-space fuse box.

Panel space is dirt cheap. Go nuts.

You are dreaming of a 16-space panel.  And even that is dreadfully small and you will find it rather limiting even with 100A service.

The practice of many electricians is to give you the smallest panel possible.  That's first, to force you into more subpanel work if you expand further (more money for them) and second to save themselves $20 in part cost.

The cost of a larger panel is trivial tiny compared to total project cost.  It is very correct to be extreme.  Please spend an extra $100 for a 42-space panel, unless you just can't make it fit.  Honestly I'd go 60-space.  Not least, those larger panels are 225A-ready.

You never know.  You might do a kitchen remodel and go hey, I'd like a separate circuit for refrigerator done microwave done dishwasher done disposal done 3 outlet circuits done.  You have the space.

When you buy a PC, do you really calculate your needed hard drive space and buy just what you need...  Or do you just buy the big 3TB drive?  Of course you do.  Same thing here.

More work to do at the meter

OK so the power company says their side of the cable is 320A.  If they say so.

They say their meter is 320A.  If they say so.

But your meter housing is not 320A.

To support more than the listed 125A, you will need to upgrade your meter housing.  There's no question of that.  That's your equipment and you have to pay for it, probably, unless your power company does something different with cost sharing.

You won't be able to replace parts of it, you will probably even have to replace both sides of it as a single unit.  However it is very nice to have your main breaker in the meter.  It means you can fully de-energize your main panel, which makes it safer for you to do yourself.

The 320A may be shared

Since it's multi-unit, the power company provisioning 320A makes more sense.  Trouble is, this 320A service is probably shared between both units.  So it's not as much as you think.

You really need to talk to your power company about what they consider this "320A" to be.  It may be a relabeling of what other power companies call 400A service.  So they may be willing to feed two 200A panels, or 100/100/200.  This is a conversation you can have only with them.

More food for thought is sub-metering units, and separately metering common spaces. The new thing in rental properties is to have one main meter and the landlord has sub-meters per tenant.  Many landlords prefer (and some law requires) commons space usage to be on a separate (sub) meter, i.e. heating, yard and commons lighting, anti-freeze pipe wrap or roof/gutter heat, coin laundry, Christmas decorations etc.


Can you have a 90 degree elbow going upward on drain line?

No, you should not do that.  As mentioned in a comment, the drain is going to fill up with gunk and clog. Depending on use, you'll find that you have to snake this line quite often.
While traps do hold water, they are limited in the depth of water they can hold.  Traps are also designed in such a way, that normal use stirs up any "sediment" and helps flush it away (self cleaning).

Uniform Plumbing Code
Chapter 10 Traps and Intercepters
1003.0 Traps - Described
1003.1 General Requirements. Each trap, except for
traps within an interceptor or similar device shall be self-cleaning. Traps for bathtubs, showers, lavatories, sinks,
laundry tubs, floor drains, urinals, drinking fountains, dental units, and similar fixtures shall be of standard design,
weight and shall be of ABS, cast brass, cast iron, lead, PP,
PVC, or other approved material.

I'm not sure how far away the vent is for this fixture. If that's 2" pipe, it has to be within 8' of the trap weir.  If it's 1½" pipe, the vent has to be within 6' of the trap weir.


Bathroom Light Fixture: What is this? And where can I get a replacement?

There's no standard for this type of twist'n'lock and no reason for manufacturers to adopt one, so your best bet is to find a brand name or a label somewhere, probably hidden inside the part of the fixture that is mounted the wall.

IKEA has a similar fixture but it is unlikely to be compatible. Still useful if you want to change both.

Make sure you follow code and pick the proper fixture for your bathroom. Check if there is an Earth wire coming out of the wall before you buy the light! If there is no Earth you need a light that does not require Earth (Class II). Here the fixture type depends on distance from bathtub/shower.

Note this type of closed splash-proof bathroom fixture has no airflow which tends to cook LED bulbs and reduce their life if left on continuously. Shouldn't be a problem in a bathroom though, it isn't supposed to stay lit 24/7.


What kind of compact fluorescent light bulb fixture is this?

It's a gx23-2 base for a 13w cfl like this:


Is it safe to stuff some insulation above my electric stove?

Use your exhaust fan.  It removes grease, products of combustion and most of all moisture.  Do you just never use your stove top?  I suppose if all you ever do is microwave and use your oven you don't need to.

You can fill the gap with roxul insulation which is fire proof.

Typically your exhaust fan venting will lead to the exterior wall which has a wall cap.  The wall cap has a damper.  The damper usually seals somewhat against the wall cap to prevent drafts and only fully opens when the fan pushes air out causing the light metal flap to push outward.


As Steven mentions in comments you could have rot in the wall.  I wouldn't say this is the case but it is definitely a possibility.

You need to take the tile out.  Get a putty knife or something comparable and chisel out the grout.  Try to pry it off.  If that doesn't work then get a wood block and tap the crap out of the block on top of the tile with a hammer.  Every 20 or so taps test tile to see if it is loose.  You should give pretty firm taps.  The tile will come loose this way or push into the wall if wall is wet.

From there you have to either fix the wall issue and reinstall or just reinstall with more material.  You might need a little thinset for it to be pushed out or layering mastic on mastic.


Have a furnace, compressor ok, can I install a heat pump?

If the solar is correctly designed then the call for backup from the furnace should be minimal. Why change to a heat pump? The capital cost is not likely to get paid off...

Why not consider reducing the load: look at the insulation levels and quality of the building ie air leaks etc.


Yes, a 6 x 12 Douglas Fir-Larch (#2 and better) with a 12’ span will support 8,000 lbs. at mid-span. It’s deflection will be less than 1/3 inch when fully loaded.

If the 6 x 12 is a Select Structural, then it will support 10,300 lbs. and deflect about 1/4”.

BTW, I recommend the window (vinyl, wood, whatever) that you are going to install below this beam should NOT be secured at the head in the middle one-half of the span.


How do I change a single-pole switch to a timer with 4 wires?

You should read the instructions included with the new switch.  You'll likely find that the black wire is an ungrounded (hot) wire, the white is a grounded (neutral), and the red is the switched "hot" wire.

If there are only two wires coming into the box, you won't be able to connect the timer. The timer requires a grounded (neutral) connection, which is not present in a typical switch loop.

As for the ground wire. If the metal box is grounded, you can connect the ground from the switch to the box. You can connect the ground using a ground screw and the threaded hole in the back of the box, or using a ground clip.


Is a tank less water heater a bad choice for a house with low water flow?

In short a tankless doesent require a high flow if anything a lower flow, the problem most folks have is a lower flow of hot water due to the fact the tankless heater can only heat the water so many degrees at a specific rate. For instance if your tap water is 50 degrees and you want a 110 degree water the unit has to be able to heat the water 60 degrees most units restrict the flow to maintain the temp with a max temp of ~130. The nice thing about tankless you never run out of hot water, when changing the water in our hot tub I set the heater at 110 and connect a hose to the hot water line and fill the entire tub hundreds of gallons and it is hot and ready to use when full. Where the problem comes in if you are showering and someone turns the hot on in the kitchen most tankless systems can't heat that much so the shower gets cold if using both hot and cold water, if the heater is set to the temp you want your shower and you are only using hot when another hot tap is turned on the flow drops but the temp stays fairly constant.


Correct Sealant / Caulk for fixing LED Down Light

I would shy away from caulk just because you might have to remove the ring/trim in the future and caulk would make that difficult. Have you thought about using some weather stripping? It comes in various thicknesses and colors and is self adhesiving. It's easy to use and less messy than caulk.


Is it advisable to connect a sump pump to pop-up sprinkler heads?

Ingenious, except I’d worry about: 1) timing, 2) seasonal conflict, 3) head contamination, 4) pressure stress.

1) Timing: Murphy’s Law...but you could locate the heads away from decks, walkways, etc.

2) Seasons: Seems like the sump pump would run most during the “wet” season and not during the “dry” season when the sprinklers need it most. Could you install a valve to allow a regular water source during the dry season? (It will be most difficult during the shoulder seasons.)

3) Head Contamination: I don’t know what the pump is draining, but it would need to be very very clean. Or, you’d need a filtering system...which sounds expensive.

4) Pressure Stress: You’ll need to “size” the system (number of heads) appropriately to match the size of the pump or it could blow the heads into your neighbor’s yard.


Grounding to the box and 3 Prong Receptacles

Just fix them right, do a room a day and it will be done before you know it.

You could swap in GFCI breakers temporarily if you can't get to it for a bit.

Be prepared to discover other deficiencies.


The switches were probably (almost certainly) wired like this:

This is the method to have two switches operate one light, common for stairs etc When either switch moves to the dotted position, then the light is on. If both switches are in the dotted position then the light is off as it is in the position shown.

What you need to do is to make a connection between two of the wires you capped off then the other switch will work fine. If you connect two and it still does not work then you have to use the third wire with one of the other two.

The original fault sounds like a broken switch anyway.

If you are not sure then it will be an easy job for an electrician either new switch or connect the wires...


Grounding and neutral in a well pump shed

Current flows in loops. Between hot and hot; or between hot and neutral.  But always a loop.
Wayward current wants to get back to SOURCE - not earth.  For human-generated artificial electricity, wayward hot current wants to get back to NEUTRAL (or an opposing hot) not ground.  It has no interest in ground, except that there’s a neutral-ground bond back at the main panel/service point.
Ground and neutral have three completely separate jobs:

Neutral returns normal everyday current.  This is the only wire current should move on (Beside the hots).
Ground returns human-generated fault current to source. That means the ground-neutral bond back at the main panel. This requires it to flow hundreds of amps, which is why it must be a competent wire.
Ground returns naturally made electricity (lightning, ESD) back to its source, which is earth.  A ground wire a long distance to another building’s main panel is a very bad choice, because lighting will incinerate this wire, and it will create a deadly voltage gradient between the buildings.  For this problem, you need a ground rod.

The dirt you’re driving ground rods into, is just dirt. It conducts electricity about as well as you’d expect dirt to.  Not nearly well enough to handle any human-made electricity - not as normal return current, nor as fault current.
The neutral wire may be fixable
I don’t blame you; most people struggling with a non-conducting wire go straight to the assumption that the wire is broken somewhere in the inaccessible parts of the cable.  Actually, that’s rare.  A single wire doesn’t randomly take damage like that (without affecting the others).
As such, I would very, very carefully inspect the neutral wire everywhere (it is not inside the cable sheath).  You may find a break or loose connection that you hadn’t seen before, and that is fixable.
Not least, where the neutral lands on the neutral bar in the panel - nobody checks that lol.
Lights and outlets are different problems
These days, lights are easy - just go shopping for modern LED fixtures, and many of them will run 120/240V multi-voltage.  If your lights are fluorescent tubes, things are even easier - change to a modern electronic ballast. Almost all are multi-voltage rated... so aside from efficiency, coldstart, zero buzz, zero flicker and better light than LED... you can also run them on 240V!
Receptacle outlets, however, are a PitA because we never know what someone is going to plug into them.  So you must wildly oversize the current provisioning.  This is not an easy problem to solve, except by saying “I don’t need receps out here that badly, how about we skip it?”
But there’s another problem with receptacles.  Code is clear that if more than 50% of your circuit ampacity is used by hardwired loads, you cannot have any receps at all.  So it was surprising to me to hear a well pump circuit with receptacles.   Also, common receps can only be on 15A or 20A circuits.  If you really wanted to do that thing, you could fit a subpanel in the shed, at which point the house run is a “feeder” and the well gets its own breaker and circuit... but obviously, subpanels really need neutral wires.  So fixing that would be a prerequisite.
There’s no such thing as fixing just a neutral wire, unless it is an individual wire run in a conduit.  If it is buried cable, you really need to bet all the marbles that it’s a problem at one of the ends.  But that is a fairly good bet.


How can I make lime plaster more resistant to vibration?

Think panels. The reason wood works so well is that each board can move 1/16” or so and the wood doesn’t crack or come apart.

Install gypsum board with plaster in panels that are allowed to move a bit and they won’t crack and fall apart either. You’ll need to experiment to determine the maximum size panel that will work in your case.

In addition, stiffen the under carriage so the entire building will not flex and twist during moving.

I’d use the “flexible” gypsum board panels (with your lime plaster over.) See USG 1/4” panel. Here’s an article about it:

https://www.usg.com/content/dam/USG_Marketing_Communications/united_states/product_promotional_materials/finished_assets/sheetrock-gypsum-panels-quarter-inch-flexible-submittal-WB2128.pdf


What type of underlayment should be used when installing engineered floors?

There are several good foam type underlayments available. For maximum sound proofing, I'd probably recommend one of the high density closed cell foam pads as opposed to the standard blue or white 1/8" lightweight styles.  You may have to visit a flooring specialty store, I have never seen the better grades in stock at the box stores, although they may be able to order it for you.  The product description on the better grades will specifically mention superior sound deadening. Good luck.


Can a digital wall timer be used with a baseboard heater?

The device is rated at 1800w or 1/4 HP motor loads so I would say it should be fine. I like to have a higher rating if possible but this is rated for halogen lighting. It's basically the same as a resistive load like the nichrome wire used as an element in most electric heaters.


What's the best way to replace this sink supply line?

The broken supply line appears to be integral to the shutoff valve.  You will need to replace the valve with something like this

You may wish to consider replacing both of them and installing new flexible supply lines.


Conventional Switches

It sounds as if most of the switches you have been replacing are single pole switches. That is, they make (on) or break off) a single connection from one location.

Simple switches use a black (hot) and another wire, usually black, red or blue (switched hot) to make and break the circuit. Basic switches do not need a neutral wire (white), so the neutral in a switch box is sometimes capped.

Smart Switches

Smart switches, like the Insteon, often also require a neutral (white) wire. The ground wires should be present and connected on all modern switch connections.

Conventional 3-way Switches

When a light is controlled from two locations, you need a switch called a 3-way. A basic 3-way switch has a black wire or connector, called a common, and two traveler wires, usually black, red or blue. The two travelers may be the same color or different colors, but the switch itself will usually be marked. It also should have a ground.

The common wire on one of the 3-ways is connected to the incoming hot line. The common on the other switch is connected to the fixture or outlet being controlled. The two travelers are connected to the traveler terminals on the opposite switch.

This setup allows either switch to change the state of the fixture by changing which traveler is connected. When both switches are on the same traveler, the light is on. When the switches are on different travelers, the light is off. A flick of either switch can make or break the connection.

When you want a smart switch, the 3-ways often need to add a neutral (white).  This is always connected to the neutral line of the circuit (other white wires) and not to a hot or a switched hot wire.

WiFi Switches

If you want to control a fixture from two locations with an Insteon type switch, you need 3-way setup. However, these types of switches do not need two travelers, just a single connecting wire. They communicate the change of state (on or off) wirelessly between the switches, and the hub if it uses one.

The wiring directions for a 3-way connection can be found here, at the Insteon site. The following is a picture of the 3-way setup.

You can see that at the switch where the hot line comes in, the line hot,  switch hot, and one of the traveler line (in this illustration black) are all connected. The other traveler (red in the illustration) is not used so it is capped.

In the second box that holds the cable to the fixture, the active traveler from the first box is connected to the black to the second switch, and the red from the second switch is connected to the fixture. The second, unused traveler is also capped.

If your two travelers are both red, you need to figure out which one is the connected one and which one is the unused one. Sometimes the wires have a marking, such as a stripe to help distinguish. If not a simple trial and error approach will work. If you pick the wrong one for the second switch, it simply will not work. you can then swap the traveler wires in the second box and you should be fine.  Be sure to cap the unused wires.


First, your illustrations are Mad Awesome.  You could illustrate electrical books.  Literally.  You might even talk to Mike Holt or others doing electrical docs.

You still have some knowledge gaps, so I'd school up some more.  For a guy as smart as you, knowledge is cheap.

If you are good at visual, stay with that.  Buy a variety-pack of electrical tape colors, and a couple feet of 12/3 cable because it's a cheap way to get a variety of wire colors for pigtails.     12 gauge is the universal donor size, it is acceptable on any common 120v circuit up to 20 amp breaker.  14ga is only allowed on 15A breakers/with 14ga wire.

First, permanently wrap (tag) the white wire of cable C with red tape. From your comments elsewhere that there is only one cable going to the switch, that is a switch loop. Also open up the switch box and wrap the other end of that same white wire.

Next, permanently wrap (tag) the black wire of cable A with red tape. Since the switch is a switch loop, this cable is the only possible way the lights could possibly be receiving (switched) power.

Now grab your receptacle and some stripped Romex and sit at a convenient workbench.   Put 6" pigtails of wire as follows.  Use the screw terminals or screw-and-clamp if you have that type. Avoid backstabs (they're not reliable) and never use 12AWG on a backstab.

Ground terminal:  a bare (or green) wire.
screw 1: a white wire.
screw 2: nothing, but if the tab between 1 and 2 has been broken, a white wire.
screw 3: a black wire.
screw 4: nothing, but if the tab between 3 and 4 is broken, a black wire.

Ready?

Splice all same colors together.

See, what I did was color-code all the wires to their function rather than the default colors of /2 cable. The switch loop has only hot (black) and switched-hot (red).  The wire to the lights needs switched-hot (red) and real neutral (white).

In new work, they commonly use red for the switched hot, because the law now requires neutral in switch loops (for smart switches). So they run some /3 cable up there.


Gas Water Heater will be permanately out of service

Drain it
Doesn't have to be bone dry, but if you drain it then you avoid the possibility of 40 gallons of water all over the place. It wouldn't be scalding hot, but it would still make a mess.
Drain it.


I did a little test and it seemed fine.

I also called the company that now owns that line of Dupont sealer. They said it was fine to use for vinyl tile, just make sure to wipe it off the tile like you would normally do.


Cleaning dried up hand-disinfectant from lacquered wood floor

I think you're going to have to sand and refinish the floor, or at least a portion of it.

Hand sanitizer contains a high concentration of alcohol which is a good solvent for many types of wood coatings inclulding lacquer. The portions that appear white look as though some or all of the finish has been cleaned off.  No additional "removal" is going to remove that since the problem is that the finish has been removed.

With a floor like this you may be able to sand and refinish only a section by using the natural lines and different wood tones to your advantage to choose an area that can be refinished vs. doing the entire floor.


The Honeywell device does not provide a C wire out.  There is fairly open access to it; perhaps you can pull a rabbit out of a hat.

Otherwise add a second transformer (2 wires from this new transformer).  Phase it correctly, I discuss how to do that here.


Can I put the junction box for an exterior wall fixture inside my garage?

Strictly speaking, that round metal mounting bracket on the back of the fixture is supposed to be secured to an electrical box.
It can be a shallow box, but it's supposed to be a box. You must protect the wires. You want that new garage to still be there 10 years from now.
I can't really tell from the photo, but the right shallow metal box should fit within that recess on the back of the fixture without you needing to cut a hole in the siding. But if you have to cut a hole, then you have to cut a hole (if you do, rent, borrow or buy a holesaw for your drill big enough for the box).

You could attach the box through to the OSB with screws, although personally, I'd lay a 2x4 flat side against the OSB inside the garage, toenail it into the studs on both sides, and screw the box directly through the OSB into that 2x4. So a stiff breeze or errant basketball doesn't knock your light fixture off the wall.  :-)
Drill a hole through the OSB and the 2x4 big enough to feed the cable and to accommodate the clamp that holds the cable in the box. The cable has to be clamped into the box.
Then attach the round mounting bracket that came with the fixture to that box, wire everything up, attach the light fixture to the bracket that you attached to the box. That's the way it's designed.
If it's a metal box, it has to be grounded (screwing the grounded mounting bracket to it will accomplish this).
You also have to secure the cable inside the garage as dictated by your local electrical code.
Finally, I'd use a dose of waterproof silicone or caulk around the box, and then again around the fixture itself after it's mounted, to make sure water doesn't seep inside.
Good luck!


Sometimes these types of lights are used to indicate a status. For instance, if the bottom light is on, the patient wants a nurse and if the top light is on the nurse needs assistance. Other scenarios are that one would have a low wattage bulb used as a night light and the other would be a higher wattage for reading and what not.
You can wire them both together and run it to a single switch. That's perfectly okay.


Dealing with squeaking screws in chipboard flooring?

A big part of the problem is that the old screws don't have a fully threaded shank. Over time, the screws will allow movement of the substrate. Especially if no adhesive was used between the substrate and the floor joists. A full-thread screw spreads the pressure over the entire length of the screw, with the greatest pressure being applied where it meets the surface of the substrate. I would go back with a better screw, such as a Spax multi-material screw. You might even consider placing them all over your floor between the old screws. My guess is, you will find a lot of other loose screws as well.


Depends what you mean by "make".

If you mean hokey-doke something together out of random bits, then no.

But if you have the skill/experience/attention to detail, that is needed for good workpersonship... and go down to a competent electrical supplier and get some #14/3 SJOOW cordage (noting that cordage numbering does count the ground)... and get a NEMA 6-15R socket and 6-15P plug whose strain relief is compatible with the cord size... and assemble them competently according to instructions... and the strain reliefs work properly on the cable sheath... and you check it in-service for heat where none should be... then yeah. Build away.

It could also be built with 6-20 plug/socket and 12 AWG cordage.  However the plug and socket must match, and a 6-20 plug will not fit a 6-15 (Ms. Nope) socket in the wall.


I regularly use 3-in-1 on my oilstones, to no ill effect.  A commercial honing oil is thinner, but as long as it can float the metal particles, you're good.  You can clean some out with a spray of WD-40, if it's starting to fill up.

(The knife aficionados are going to hate this answer.  It's got 3-in-1 and WD-40 in the same paragraph.)


Lighted medicine cabinet needs GFCI outlet and Dimmer - why?

The GFCI is purely for the outlets (as required by code for outlets near sinks).

The light is separate and controlled by the dimmer. You can also use a normal lightswitch.

The reason for having both is that you want outlets to be powered even when the light is off. To be able to charge your electric toothbrush while you are not using it for example. Dimming outlets is not a good idea in general.


How can I remove or level grooves in thinset mortar from a concrete slab?

I was thinking of a grinder like this disc for concrete I have one I bought years ago for my 9" grinder the disc is 12" it will take a entire single bay garage floor surface in about 2 hours. Cheaper than shot blasting and my disc has done 5 or 6 garages and still has a couple left. The trick is to keep the grinder moving in overlapping orbits. the link shows a smaller model that should be able to do the 130 sf in an hour or so.


Weird Power Outage in Certain Rooms- Condominium

Phase/Leg Out
You have lost one phase or leg (terms vary) of your power. 120/240 power comes in on 3 wires - two hots each 120V from the neutral and 240V from each other. Most breaker panels are designed with alternating legs. Left & right in each row are on the same leg. 240V (dryer, oven, A/C, etc.) use a pair of breakers, one on each leg.
Your electrician should have been able to figure this out. In any case, CALL YOUR ELECTRIC UTILITY and tell them you have an intermittent phase/leg out. They'll check it out for free and fix it if it is on their side, which is very often the case.


Attach light fixture with 3.5" bolt holes to ceiling box with 2.75" bolt holes

I managed to attach the light fixture using the universal crossbar, but with some improvisation.

The light fixture included two combo truss bolts that were designed to screw into the junction box but this didn't work because of the incompatible sizes(3.5" and 2.75").

The solution was to  bolt the crossbar to the junction box and hang the combo truss bolts (to attach the fixture) from the top side of the crossbar, with the bolt heads resting on the top of the cross bar. Then I secured the fixture to the bolts using nuts.

Not perfect but the fixture is stable and secure.

Thanks for your comments guys!


Installing a dimmer switch for a ceiling fan

Dimming the lights only is fine here

The problem that you're being warned about is that a dimmer switch designed for lights will not have a good time of things if you hook a fan up to it.  Since you have separate switches controlling your lights and fan, using a dimmer with sufficient rating for the lights installed into your fan+light combination to control the lights will be fine.


Mounting a TV above a fireplace with an unknown stone

Mounting a TV above a fireplace is an overall bad thing to do.

Fireplaces get hot. Electronics do not like heat.
Above fireplace places TV at a less than optimum viewing angle. TVs are designed for best image looking mostly straight on at eye level whilst sitting on a typical couch.
Getting connection power cords and signal cables up around the side of the fireplace and to the area of the bracket is totally hampered by the firebox and chimney that is inside the wall. Normal in wall hiding of cables is not possible and leads to an ugly installation.


How to check whether demolition brick is safe to use?

You would need to send samples to a chemical analysis laboratory to get a more definitive answer, but the brick was likely never in direct contact with the chemicals and after 10 years I would expect they off gassed anything they might have picked up. If you don’t  notice an unusual smell from them, they are probably fine.


Wiring an outlet with two white, one red, and a ground

With a 14/3 (white-black-red-ground) and 14/2 (white-black-ground) coming into this box, CoAstroGeek suspected that this might be a switched outlet. Exactly right.

There is a switch in the room next door that we had no idea what it was for. once i switched it on, there was power to the outlet. the short of it is- the room used to be the garage and was converted into an office 40 years ago. there are two switches on the wall in the room next door; one for an exterior light and one for that outlet. must have been an overhead light or something.


Which 50 amp breaker do I need for my old Eaton panel?

Eaton has two breaker lines:

the residential grade (cheap) one, BR
the industrial grade (good) one, CH.

This is CH. It is an excellent panel. Hold onto it!

BR will be placed more up-front because it's more popular.  If you stop there and give up, that's the trouble.  Most likely the store also carries CH.  Look for it: the narrow package and distinctive beige handle is the giveaway.

Expect to pay under $12 for this CH240 or CH250 breaker, which should be readily available.

You asked about other brands of breaker.  You cannot put J. Random brand of breaker in your panel, even if it seems to fit because it doesn't actually.  You must use breakers either manufactured by the OEM for that panel (e.g. Eaton), or competitor breakers that are UL-listed (technically, UL-classified) for that panel. I'm not aware of any classified breakers for CH.  It wouldn't save you any money, and the beige wouldn't match!


How to increase flow to upper water outlets

That's normal in every house everywhere.

If someone's in the shower, don't open the faucet!  That's a basic rule of cohabiting a house with anyone.

If you really want to engineer your way around that, you'll need flow restrictors on every faucet, and a temperature compensating blending valve on the shower.   How much flow does that faucet need?  You may be thinking "the absolute maximum possible", well, then, OK, you can't use it at the same time as other faucets, because it's taking it all, as you intend.

Since you've made all the pipes huge, the limiting factor is now the water supply coming in from the city.

The difference in bar pressure is explained by the difference in height between floors. 0.5 bar is the weight of a column of water 16'9" tall or about 5 metres.


Homeowners Electric Permit - Mongomery County, Maryland, USA

Sorry, you don't.  I also started in electronics... Very little of my experience was applicable to NEC code electrical.

Knowing how electrons are supposed to behave gives you a small edge.  But you must throw out all your existing knowledge about "how to do things" and allow yourself to grasp a different paradigm and ultimately the reasons why. Code does nothing without a reason.

You will find the codebook to be useless.  It's a book of law and is very poorly formatted to be a reference guide or learner.  It says so, flat-out, in Article 100.

So, are you ready to answer questions like this:

You are wiring a receptacle circuit in 12 AWG wire.  The circuit breaker and receptacles are rated for 75 degrees C.  The cable is UF, which is rated for 90 degrees C. Do you use a breaker size of

15 amps
20 amps
25 amps
30 amps

   20A.  The stuff about degrees C was a red herring, to make you turn to table 310.15b16, which is what you'd do when under the gun and flipping through NEC at the exam.

You are running six circuits in 12AWG UF (90 degree C) cable which all pass through a conduit 22" long.   What is the largest breaker you can use in these circuits?

15A
20A
25A
30A

   20A.   This situation comes perilously close to the 310.15b2a rule requiring a "50% derate off the wire's highest temperature column in 310.15b16, which is 30A at 90C" ... but the conduit is less than 24" so you dodge the rule.

You are wiring a new multi-wire branch circuit, featuring two hots and a shared neutral.   You only have one space remaining in the panel.  Which type of breaker is appropriate?

a duplex breaker
a quadplex breaker
a 2-pole breaker

   A quadplex.  A duplex is not appropriate for MWBC, and a 2-pole won't fit!

Select the minimum requirements for a Grounding Electrode System using ground rods:

one ground rod
two ground rods, or one if it passes the  test in NEC 250.24.
two ground rods
one ground rod, encased in concrete

   The last, 1 in concrete.  I played a trick on you, this answer is affected by a local amendment!

The point

None of these things have anything to do with electronic design. Life is different on the other side of the wall-wart!

The solution

I say with sincerity, electronics guy to electronics guy, to hit the library and thumb through some books on residential electrical.  Find one that speaks your language and devour it.  You will find many things that seem unimportant, like the above.   Then, browse a couple more and see what their takes are.

Then, spend a lot of time surfing this site, as it can backfill, expose you to common situatuons and give code refs, which books do not.  Mostly read existing questions (we're not big fans of hypotheticals unless it's a really good question).

Hopefully the test won't ask questions inapplicable to residences, which is what most of NEC is.

Some actually involving design

In 120V/240V split phase, a multi-wire (shared neutral) branch circuit has both its hot wires breakered 20A, but no breaker on the neutral.  Which condition causes the maximum (worst case)  current that could possibly flow on the neutral?

20A on both hots
20A on one hot, 10A on the other
20A on one hot, zero on the other

All the wires are in the same cable.  Among the above choices, which one results in the least total wire heating in the cable?

Sadly, even these basic thinkers won't be on the exam.


I have no power in my attic and there are not any tripped breakers of GFCI in the house

Most circuits are wired as strings, from outlet to outlet to outlet in a line.  (An outlet is a receptacle or a hardwired load).  Sometimes they are wired in a tee or tree arrangement, but the same basic idea applies.

Let's say the circuit is a string, PANEL - V - W - X -  Y - Z.

Let's say X and everything past it (Y and Z) lose power, and W is the last outlet that is still good.  It is usually a faulty wire termination or damaged device at X or W.

People often overlook the importance of the location before, W.


What is the maximum number of connections to pipes?

It's not based on number of connections, but instead a computed value known as "drainage fixture units".

  2012 International Residential Code

  SECTION P3004 DETERMINING DRAINAGE FIXTURE UNITS

  P3004.1 DWV system load. The load on DWV-system piping shall be computed in terms of drainage fixture unit (d.f.u.) values in accordance with Table P3004.1.

  SECTION P3005 DRAINAGE SYSTEM

  P3005.4.1 Branch and stack sizing. Branches and stacks shall be sized in accordance with Table P3005.4.1. Below grade drain pipes shall be not less than 11/2 inches (38 mm) in diameter. Drain stacks shall be not smaller than the largest horizontal branch connected.

  Exceptions:
  1. A 4-inch by 3-inch (102 mm by 76 mm) closet bend or flange.
  2. A 4-inch (102 mm) closet bend connected to a 3-inch (76 mm) stack tee shall not be prohibited.

  P3005.4.2 Building drain and sewer size and slope. Pipe sizes and slope shall be determined from Table P3005.4.2 on the basis of drainage load in fixture units (d.f.u.) computed from Table P3004.1.

Notes:
It seems that you are doing quite a bit of plumbing, and that you may not have all the knowledge required to do the work yourself.  It might be a good idea to contact a local licensed Plumber, as they will be familiar with your local codes.


You may find cutting the paint around the edge necessary - it acts like glue.


What size equipment grounding conductor is needed for this gate lights circuit?

Where the grounding conductors are increased in size (from the minimum) the grounding conductor also needs to be increased in size proportionately per 2014 NEC 250.122. I used the southwire voltage drop calculator. The calculated value needed for a 5 amp draw is #8 copper for 5 amp load at this distance 2.8% voltage drop. The problem with down sizing the conductor in this case would come if the lighting was changed at a later date using more of the available ampacity of the circuit then the conductor would be under sized. 120V @ 12 amps would require a #4 conductor and the #8 would be two small to limit the voltage drop for a short circuit.


Letting a thermostat regulate temperature, or do it myself?

Both neither is wrong nor right.
Because it's all depending on your preference after all. If you are likely to turn on/off frequently and making your time to turn on longer than expected it could be more costly.
You can use a power meter to calculate your power consumption for this heater with thermostat regulating and with the manual so you know how big the difference in a year (calculate it yourself)


It appears that the screws are screwed in far enough but the contractor did a poor job of taping and mudding.


How to best clean the inlet vent screen on a microhood?

I ended up using degreaser and it worked better than I thought.

First, remove the vent screens.  In a sink, I sprayed liberal amounts of degreaser on both sides and let sit for a couple minutes.  Spray down with water and repeat cleaning if necessary.  Dry on a towel.  Afterwards, they looked like new.

I guess sometimes the simplest approach is best; don't overthink the situation.


Will I have to chuck my Drill Press Chuck?

That is a Morris taper. Clean it off and slip it back in place a light tap with a mallet should seat it. The tail stock on my lathe has a MT4 much larger and I have spun it out several times, I wipe it down with brake cleaner inside and out and slide it back in then a tap and it is fine. I have a fly cutter that is about 5" and I use it all the time on the mill I use light pressure and don't usually have any problems. Your drill bit probably grabbed and sucked down breaking the connection. Don't drive it in hard or you may deform the mandrel.


I think the best bet is to use up the remaining primer in the pail by applying it to the drywall. Then start with the new pail applying on the remaining drywall.

Even better would be to let the residual area dry before coming with an overlapping coat of the new primer.

Some paints would mix just fine whilst others may not. So why take the chance when the solution is simple.


Will a doubled P-trap cause problems if it has a vent between the traps?

Debris is more likely to settle in the second trap due to lower drain velocity at that point
It's more difficult to clear debris there because you can't conveniently disassemble the trap
System cleanout with an auger is impeded by the extra trap bends, which tend to be sharper than other underground bends


How can I get a wire that is outside a wall to be inside a wall

You will need to remove that portion of the drywall, which shouldn't be that big of a deal anyway because you will need to do drywall repair for the two holes as it is.

Turn off power to that circuit!  If you are unsure which circuit this wire belongs to then shut off the main power just to be safe.  You don't want to risk injury by accidentally cutting that wire or possibly other wires that you can't see.
Determine to the best of your ability if the perpendicular wall is load bearing.  If you have any suspicions at all then stop, you are done.  You won't want to do the drilling steps described below on a load-bearing wall. It would be best for you to disconnect this wire and re-run it.
Locate the closest outlet or junction box that this wire goes to on any side.  Test it to make sure there is no power.  Temporarily disconnect the outlet from the wire(s) and if there are any clamps on the wire in the box then temporarily loosen or remove them if possible.  If it is a newer style box with Romex-style wire clamps on the outside, this may not be possible, so you should stop.  The wire is clamped and possibly also stapled into studs or joists.  You won't be able to pull it out from the hole in your picture.  I would deactivate and rerun the line at this point.
If the clamp in the outlet box is loose then have a buddy look at the wire in the picture and see if it moves when you pull and shake on it.  If so then that means it was a crappy DIY job and he didn't staple the wire down like he was supposed to.  This is good because it means that you can pull it out and rerun it through a different hole.  Not yet however.  If the wire doesn't move at all then that means there is another outlet or junction box before this or that the wire is stapled down, meaning you will never be able to rerun this without tearing down obscene amounts of drywall.
Locate the studs.  If you have a fancy pants stud finder then use it to locate and mark the positions of the studs on the facing wall and also possibly the perpendicular wall.  If you do not have such a tool then use a strong magnet to find where the nails are, this is where the studs will be.
Drill a small hole halfway around the center of the stud at the top left of the rectangle you will cut out.  This will allow you to fit a keyhole or drywall saw into to start cutting.
After cutting out that rectangle the perpendicular wall will be exposed.  Inspect the path of the wire and see if can it be easily pushed through back to the outlet.  If so then tape up the end of the wire at the box and tie off a thick fishing line or strong twine to the end of it.  When you pull the wire, it will take the fishing line with it, giving you something on the other end of the outlet that you can pull on to help direct it through holes and other paths.  If the path is long or there are some crazy bends or very small tight stud holes that you can see then this may not work very well.  At that point the wire should be disconnected and a new line should be rerun.
Drill a hole through the necessary studs so the wire will run properly behind the drywall.  Disconnect the fishing line and run it through the new holes, then re-attach the fishing line to the wire.
On the outlet end start pulling gently and slowly while a buddy helps feed you wire from the other end.  The fishing line will help properly navigate the wire back to the outlet box.  If you get hopelessly stuck and don't mind cutting more drywall to see what you are getting snagged on, then proceed, otherwise call it a loss and disconnect the wire.
The wire is back at its home!  Reconnect everything back in the outlet or junction box as it was.  Turn the power back on.  If nothing tripped then you have no shorts.  Test all affected outlets, and switches on that circuit to make sure they all still work properly.
Cut out a rectangle of drywall that fits mostly inside what was cut out. screw it into place, tape and mud the edges two or three times using progressively larger mud knives until everything is smooth.  Leave for a day or two to cure then primer and paint.  You are done.


20 amp circuit breaker trips after using 15 amp miter saw

A large inductive load, such a motor starting, often causes a ground-fault circuit interrupter to trip even when there is no fault in the device. A snubber, a small capacitor and resistor across the line, can help mitigate the issue. A voltage surge protector can also help, but avoid protectors with large varistors from line to ground, which can also trigger the GFCI.

You might also need a Class C or other type of GFCI which allows greater fault current to flow for a longer time, depending on shop voltage, appliance grounding and insulation.


Only if it's a Dirty Water Pump. But, it won't pump any more volume than it does now & a bigger hose won't mean anything if the hose's mount isn't replaced with something bigger too.


ADSL + Ethernet Surge Protection. What is chaining?

As explained in this Electronics.SE article, daisy chaining of AC power protectors, where they both attempt to protect the same electrical circuit, can cause interference and failure. But that's not what you're doing. You have 3 protectors, for electricity, ethernet, and phone/DSL respectively. Those are 3 separate circuits, even if some of them flow into the same devices, so your setup is fine.


How do I wire an old furnace motor so I can use it as a garage exhaust fan?

Squirrel cage blowers make great fans. Black is ground, white-negative and red-positive. Looks like blue, white and red coming from the motor. Read the info on the motor, it should have split capacitor in it, may have to change the wiring from 220 to 110. Looks like a 1/4-1/5 horse. Ask a local HVAC guy, feed his ego and be rewarded. If its a 110 just throw a three prong on it and breeze away. I pulled some romex off the coil and pulled a spare heavy duty three prong outta my tool bucket and had a great workshop fan w/ a super long cord.(put a triangle shaped piece of plywood on one side to stabilize it, and a small board 1x2 across the front as a foot/stabilizer, made it quiet)


Does a fixture connected directly to the ground stack (vented) need to be vented separately?

Generally speaking: A Stack (even if it's vented) is not a Vent if it has a toilet on it above the point you want to use it as a vent. Older installs may not respect this. There were problems with not respecting this, code changed to solve them.
You can run a (dry) vent up to a point "6 inches (or more) above the flood rim of the highest fixture on the floor served" and join to the Stack where it IS a vent. In that case it would be the highest floor served, but you can join vents for the basement 6 inches above the flood rim of the highest fixture in the basement - but you can't then join that to a stack with a toilet above. You can run it parallel to the stack until you are 6" above the highest fixture and then join the stack.


Simple in theory.  Assuming you are mounting the beam to the side of the post at the top.  You have an ideal situation for a cantilever.  It even follows the old rule of 1/3 (cantilever), 2/3 (back span).

To size it, find any floor joist chart and figure the span of 8'.  A 2x8 spans upward of 12'.

Load wise you will probably never hit over 200-300 lb on the rope swing so a couple 3/8"-1/2" through bolts at each post through the beam would be overkill.  With those loads, even 6-8 long screws would be more than enough (@ aprox 70-100lb+ per screw).

Biggest problem will be rot between the beam and the post over time as water gets trapped between the two.  For this we usually use the through bolts and put a small stack of galvanized washers (5-10) between the post and the beam.

As for bracing it laterally, using a wider member like a 4x would help.  So a 4x8 would probably be ideal, and a 4x6 should work well enough.  But then you need through bolts for sure.


Can I use low voltage lights with a motion sensor?

You will have to install the motion sensor (if it is rated 110v) in the feed to the low voltage system.  that is, hot going to switch, then motion sensor, then low voltage transformer then low voltage lights.

that is, sensor powered by 110v, feeding transformer


Oooo!  That's a challenging problem.

An idea that springs to mind is try renting a pneumatic gopher: variously called a hole hog, underground pneumatic piercing tool, air hog, etc.

There is a (crummy) Wikipedia article about them.

Those bore in a straight line, so I expect starting it some distance back from the wall and point it downward at about 45° to miss the bottom of the wall.  You'd then have to dig a hole to find the borer.

Here I show digging a big hole at the left for device access.  Bore a hole for the new connecting pipe (magenta).  Dig a hole at the lower right to intercept the bore and provide access to connect to the lower line.  (I should have erased your red line.)


Is it possible to build a one-cubic-meter soundproof space? what is the minimal size of a soundproof space I could build?

A small-scale model won't produce accurate results. You will have different standing waves, resonances, and modes in small cube than an odd-shaped real-life room. Different cube-lining materials will provide a baseline relative comparison, but the results shouldn't be extrapolated to a real-life situation without careful acoustical modeling.


Let's be practical  about this one. The area of concern on your part is the wire that is resting on the ceiling drywall. In a perfect world, if you had had access to the space then the wire should have been secured to avoid any nail damage etc. It sounds like you did the rest of the installation well where you had access. If the cable in the closed ceiling is not visible without removing drywall, then it is highly unlikely a home inspector will even see it. I'm not advocating hiding problems from a home inspector,(I am a home inspector) but keep in mind that a home inspector is not a government building inspector and typically is not allowed destructive/invasive inspection techniques. If the cable is fully enclosed, it will not be seen.  Let us assume that the inspector sees and makes an issue of the unsecured cable. Normally, the finding would be addressed before a closing. It would be rare that a minor problem like this would sink a sale unless the buyer was looking for some way out of the deal and refused to allow you to remedy the problem. Personally, I would never write up such a minor discrepancy unless I felt it posed a safety problem. Most electricians I know would probably do the same by fishing the wire in an open bay and securing it in the first exposed area available.