How can I replace failing ballasts in recessed CFL housings if I don't have access to the attic?

new-work Halo cans are adjustable to accommodate different ceiling height. Remove the reflector trim and the lamp. Then remove the three sheet metal screws from near the bottom of the can. Slowly work the can down and out. There is enough slack in the  jacketed cable to let the can hang about six inches below the ceiling. Reach through the hole and unclip the face of the junction box to expose the wiring. With power off you should be able to disconnect the 120VAC. If you want to see how these are wired before you pull the can, go to Home Depot and look at a bare new-work fluorescent can. Anyway, look at the armored wires going from the can to the junction box and make sure the ends inside the box are detached, whether you have to cut them or just remove wire nuts. Then take slip joint pliers and squeeze the end of the cable lock to free the armored section from the junction box and remove and discard the can. Buy a new Edison base Halo H-7ICAT assembly and remove the can portion from the frame as described above. You'll have to cut the push connectors off the end of the wires. Strip 5/8" of insulation off the ends of the wires and reinsert throught the hole in the side of the old junction box until the anchor locks. Attach the can wires to 120VAC, bypassing the ballast, which should be completely disconnected. Replace the metal cover on junction box, reinsert can through the ceiling hole, align screw holes, adjust can height to ceiling thickness, and insert screws. If you want, you can push new insulation through the ceiling hole before reinserting the can. You can also caulk the cracks between the ceiling surface and the edge of the can to make it airtight. Once that's done, remove the socket holder and shield inside the can, attach the Edison base LED pigtail that comes in the LED retrofit kits, install the LED kit and you're done.

I've had to install a bunch of these where I had no attic access. Works great and you don't have to cut the ceiling.


Electricity travels in loops

In utility electrical, every hot must have a return wire partnered with it.  They must be in the same cable.  All the currents in each cable must be equal: the current coming down as hot must return up as neutral. With 3 or more wires, the currents added together must equal/cancel out.)

When a neutral is disconnected, it will light up as hot. Electrons are trying to return, and they can't. So this "floats" the neutral up to 120V.  This is a really good reason not to bootleg ground -  nor use 3-prong dryer/range outlets, which "legally" bootleg ground.

Get some colored tape

3-way circuits will make you ape crazy, because the physical topology of your wiring, and the equal-currents rule, forces some strange routings sometimes.  Here's what is happening electrically, and note each wire has a different purpose, and in this diagram, each purpose has its own color.

There is no reason to distinguish travelers from each other; they are interchangeable.

Of course this does not match either your wiring topology or your colors.  I would make it so using colored tape or shrink wrap.

So assuming your /3 cable rings out alright...

Figure out how you want to wire your 3-way circuit.  I would take always-hot down to the remote 3-way and bring two messengers back.  Black is a good always-hot color, so I would tape the red and white wires yellow.

Your neutral from supply is already tied to neutral up to the light. Done.

Your hot from supply is easily tied to the /3 cable black.

On both 3-way switches, the yellow wires go to the traveler (brass) screws.

Each box has only 1 wire left, that goes to the common (black) terminal.


I have mine on a 4" thick reinforced concrete pad, no problem. If not reinforced, I'd go with 6". Basic cheap "Quickcrete" is 3,000PSI compressive force, plenty strong enough when you factor in the surface area of the tub's structure that will be contacting the slab.

Keep in mind though that concrete strength takes a long time to get to the peak strength levels. So don't place your tub and start filling it immediately.

Age  vs Strength percent

1 day    16%
3 days   40%
7 days   65%
14 days  90%
28 days  99%

Oh wait, you said it was already existing... never mind.


Find a local metalshop, ask them to bend it for you. Should be cheap. Or you could spend a hundred bucks or so on a cheap bending brake. Or you can continue to wrestle with it.


Why am I getting an electric shock from the water in my hot tub?

Edit: This is sounding more and more like a problem with either a neighbor's electrical or the utility's supply.  See last entry.

DON'T get in that hot tub again!

The "very small" shock was due to high impedance between you and the current.  Impedance is extremely luck-based. Someone getting out of the pool might splash water where it had not been before, now the impedance is much lower and that "small" shock puts you in a wheelchair.

Hot tub miswiring is so common it's legendary.  RCDs do not protect you from all wiring errors.

Don't get in the hot tub again until you positively find the cause and remove it.

8ma vs 30ma protection

RCDs also do not protect you from shock, necessarily.  In Europe, RCDs have been used for a long time, and for a different reason - protecting houses from fires, not protecting humans from shock.  Also, since they use whole-house RCDs, they must use a higher (more permissive) threshold, otherwise small leaks from many appliances will "stack" to cause nuisance trips.   So whole-house protection is typically 30ma threshold.

Whereas in the US, GFCI is specifically for human safety, and it is 6ma or 8ma.  This is too sensitive for a whole house, so it is applied circuit by circuit on circuits where it is helpful.  (near sinks).

Your whole-house RCD would need to be 30ma, which is not enough for life-safety protection.  It's less likely to outright kill you, but it's plenty enough to stun you - and when you are in water, being stunned means drowning.

Your hot tub should indeed have its own RCD, at the 6-8ma sensitivity level. However if you walk into a store and buy any random RCD, it's quite possible you'll find yourself holding a 30ma one.  Perhaps your hot tub installer did exactly that.

RCDs do fail

I.E. they stop properly detecting ground faults. That's why the device has a "TEST" button.  Use it.

It may be miswired to bypass the RCD

In fact, this is likely if the hot tub installer hit a situation where the RCD tripped when he hooked it up correctly.  The RCD would trip when hooked up correctly, if the hot tub had a ground fault.  Typical installer move is to jury-rig it any method that will work, then get paid.

This can also happen with amateur installers. They typically refuse to learn how to do the job properly (because that takes time learning about subjects they just don't care about), and simply "try random combinations" until one works.  Many will work and also kill you.  This might be one of those.

If the hot tub has a ground fault, fix it - seriously

Sometimes RCDs trip because the downline device is connected correctly, but actually does have a ground fault.  This tends to surprise the heck out of people, they are in full disbelief -- "MY appliance has a ground fault? This cannot be!" (even they know nothing about ground faults).

I've seen people replace RCDs twice simply because they cannot believe they actually have a ground fault.  And of course they feel totally justified in bypassing safety protection altogether.

So don't be in denial about that.  There is a real possibility that the hot tub has a ground fault.  If so, fix it.

It might not even be the hot tub

There's an outside chance this shock is entirely unrelated to the hot tub.  It's possible the dangerous voltage is being sourced from some other thing in your yard, and the hot tub is correctly providing grounding, thus completing the circuit.  If so, the cure is a thorough search of your house's electrical system for any defects. And if neighbors are close, you may need to bring out someone to test for problems coming from them.

In any case, this is nothing to trifle with.


Why would one breaker trip more than another under the same load?

Get another 20A breaker and replace one of the 15A breakers with it.  There is a special exception in Code which allows 20A breakers to be used on  circuits where

all the wiring is 12AWG Cu or larger
There is more than one 15A socket.  That's easy; most come with two.

A 20A circuit can't feed only this.

  One of these is fine.

FYI, there's also a UL rule that 15A receptacles must be good for 20A passthru. That applies to most GFCIs too.

Now with two 20A breakers in the panel, you can experiment more and get back to us.

Also make sure the breakers actually are the same make/model as the panel -- the simple way here is to make sure your panel brand equals your breaker brand.  Wrong brands/types will seem to snap in, but don't properly mate and will arc and burn up the buses.

This isn't scamming you, we're not name-brand-obsessed, if you want to use a GM/Delco brand brake pad made for an F150 on your F150, have at.  That's just not very common with breakers.


Fix intermittent connection problem in a monorail low voltage light fixture

I found a solution.

The first photo below shows the light fixture removed from the monorail, but fully assembled.
The second photo shows the shade and bulb removed. Also, the fixture has been unscrewed from the mounting bracket.

I used an ohm meter to check continuity on the fixture, and decided there was an intermittent connection between the lighting fixture and the mounting bracket (the two pieces that are unscrewed). Screwing the two pieces together is supposed to make a solid connection such that the circular top of the fixture (the area right above the black band) touches a conductive area inside the mounting bracket. The connection between these two spots has become loose over the years (I don’t know why).

I took some thin sheet metal (actually the bottom of a can of mixed nuts) and cut out three circles the diameter of the top of the fixture. I carefully stacked the three pieces of metal on top of the area (above the black band) and screwed the two pieces together. The electrical connection is now tight, and the light has been working perfectly for the past three weeks.

[UPDATE 3/12/15: As requested, here are more images and notes. If you use the metal from a can, you should probably sand it to remove any clear coat on the metal. I used heavy duty scissors to cut the metal. The metal discs are cut slightly smaller than the diameter of the post they sit on top of. I think you have to prevent the discs from touching the sides of the light when you screw on the top piece (to prevent a short). Also, the light stopped working again after about 8 months. So I made a second fix where there was a loose connection on the side of the light. I cut out a crescent-shaped piece of of metal (shown by itself in the next-to-last photo) and shoved the shim into the loose joint (final photo). I might trim up the crescent shim when I have time. The light has been running fine since this second fix.]


120V measured between different outlet grounds

Use a non-contact voltage detector pen on the outlet by holding it near the face -- if it lights up, you likely have what Johnny is describing in the comments, a so-called "reverse polarity bootleg ground".

(On a properly wired outlet, the voltage detector should not trigger until you stick its tip into the hot slot on the outlet.)


What is this cylinder looking thing in the drain line?

Almost certainly a drum trap - so while cleaning it out might be good, removing it is generally a bad idea unless you are replacing it with another type of trap. Which you may well need to do, as they do rot out eventually, I'm just trying to head off at the pass the idea that it would be OK to remove it without putting a different trap there - is it leaking?


Portable Air Filter Possibly Creating Black Dirt Everywhere

So I was in contact with Helen of Troy, who manufactured the air filter under the Honeywell brand. Sent the unit in for testing and it turns out it was an ionization unit, which I look through multiple product pages in the manual and nothing in it ever mentioned that technology. So the test results concluded that certain particles in the air, but my guess is from burning Yankee Candles, would pass through the ionizer and then the dirt particles would stick to the candle soot and attach itself to surfaces. So if you like to burn things, don't use a portable air filter with ionization technology. Use one with replaceable HEPA filters.


Those types of latches for had specific shapes to follow the door edge profiles. You may be able to find a new latch that will work, but I would suggest shopping for an antique latchset that will suit your needs and have it reconditioned by a locksmith.
After that is accomplished, then cut out what is needed to get the new or reconditioned latchset to work. Don't just remove what was filled in, although it may be needed anyway, but some filler may be able to remain, since the new lock may have different cutouts needed. Then again, in making the new mortices (cutouts) the filler may fall out anyway. Just as well, if it does, it can be reset properly and more permanently.


There are several issues here to deal with that I see.

First, you need to find an appropriate location for this aperture. It is best if the location is one that you can get to easily, but out of the way - since a hole in the floor might be unsightly or something to trip over. It also needs to be accessible from below to get in and out. I would suggest a back hallway or back bedroom as being good.

Second, you need to worry about which joists are involved. Can you get through a hole between the joists in your house? If you needed to cut through a supporting beam, this can have very serious and negative consequences on the structure of your house. Do NOT do that without knowing what and where you are cutting, and providing the necessary support for anything that is cut.

You will need to carefully mark out the cut lines. Careful measurements will be important. You may choose to make a tiny hole or two with a small drill bit to figure exactly where you will cut relative to any joists.

Last, the actual work. Cutting through the floorboards, once they are carefully marked, requires no more than use of a handheld circular saw or a reciprocating saw. There are several other types of saw that could do such a cut on the market, rotory "zip" tools for example, even a hand held manual saw if your skills were adequate. If you needed to cut a beam, then you will need to provide new support points for that joist on  either side of the cut that are FULLY capable of carrying the load. You may even need to reinforce the floor boards themselves as they were cut on either side too.

To close it all up, take the flooring that you cut out, and create a door from the flooring itself that matches the hole you just cut out. Recognize that this will be a trip point, so do not put a big, bulky handle on it. A simple, low piece of moulding around the perimeter may be sufficient to hide the cuts and support the "door". Even that is a trip point, so be careful here.

All in all, this MAY be something that is best given to a reputable contractor to solve for you if you don't know how to solve the problems that will arise. The cost would depend upon whether you can find a location that does not require the cutting of any beams.


That bench is beyond economical repair, or practical, repair.
If all the rotten wood were cut out the hole would probably be three times larger.
As a band-aid get a scrap of Formica sheet (or similar kitchen laminate) and fix it to the surface with duct tape.  the tape may need to be renewed every week.


The difference in height can be from 1) bad initial installation, 2) someone sitting on one of the panels, 3) warping of one panel,

1) Leveling two pieces of plastic laminate (Formica, etc.) is mostly an “art” and patience. Yes, the initial installer could have given up after a few tries.

2) Settlement...ugh...I cringe when my teenagers decide to “help” in the kitchen. An easy test to determine if this is the cause is to pry on the two pieces (gently) and see if they move independently from each other.

3) I’d look under the counter and verify that both panels are particle board. We generally use plywood near sink installations. If it is plywood, it could continue warping with additional water splashed on it, change in humidity, etc.

Here’s an article that explains: https://homeguides.sfgate.com/laminate-countertop-put-over-plywood-particleboard-99004.html

Removing and reinstalling the countertops is difficult because the base will be deformed from prying the tops loose. If the problem is truly just a difference in height, (and not that the two panels have twisted, rotated, moved out of “square”, etc.) then I’d try slowly raising one panel with wedges (shims).


you will have very mixed results applying a stain over any kind of preserving oil.  the preexisting residual oil will prevent stain penetration, and as it weathers further, the old oil will continue to breakdown, leaving areas with none of the new stain.

you can use tung oil or danish oil (both readily available in bc), but just remember, natural oil finishes essentially need to be redone annually

if you want to convert to a synthetic stain, it will need to be oil based, and you will have to apply 1 or 2 coats of mineral spirits to the wood first to re-dissolve the old oil finish and make it possible for the new oil based stain to saturate into the resulting old oil/mineral spirit solution


Why does my shower have low water pressure?

Does the pressure return to normal if you reduce the output water temperature?  Some electric showers will regulate the amount of water flowing through them to allow the water to reach the set temperature; at higher set temperatures, the flow rate is reduced so that the water remains in the heater longer.  Given that your symptoms appeared recently, it could be that a heating element failed.


How to insulate from the noise generated by rain falling on a roof window?

If this is like most skylights (roof windows) there is a space below the window where you could stuff something to deaden the sound - acoustical insulation.
If you cut a piece of styrofoam insulation just slightly wider than the opening, you can press it in and it will stay on its own.  You can cover the exposed side with something so it looks OK.
You could cut a piece of plastic bubble wrap the size of the glass pane and attach it to the outside of the glass with silicone sealant.  This would not be too hard to remove, and would let most of the light through.   I doubt it will last long in the sunlight but maybe you'd only need a fresh piece once a year.


How can I run an unswitched receptacle from a three-way switch box?

How is this switch wired? Is it a 3-way switch or a simple on/off switch? (It's a 3-way switch if it is one of two switches that can toggle your lights on/off. It's a simple on/off switch if there are no other switches that control the same lights.)

If it's a 3-way switch, then its two positions toggle a "common" conductor among two "traveler" conductors. Usually white is wired to common (one side of the switch) and black and red will be different travelers.

In that 3-way configuration, the box containing the circuit does not have a neutral available. The neutral will be available at the light or at the other switch box. This means you cannot run a new outlet from the wires in this box - you need a neutral wire.

If it's a simple on/off switch with 3 black/white/red wires, then it's possible that you have a neutral (which will not be connected to the switch because all the switch needs to do is connect/disconnect a hot conductor). Typically that will mean your white neutral wire is unused (should be capped with a wire nut) and the switch will connect black to red when turned on. If that's the case, then you can run a new outlet by connecting to the white neutral wire and the black (always hot, not switched) wire. You could also run another switched fixture from this outlet using white and red (switched hot) wires.


How do I patch an in-ground ceramic drain pipe?

Get a large diameter PVC pipe, cut it in half lengthwise on a bandsaw so it has a sort of shallow C shape cross section. Clean out the broken bits from the clay pipe and use the PVC pipe to cover the hole. Use some adhesive to keep it in place.


Connecting Common Wire from thermostat to Air Handler

For systems with two transformers, you would normally have a red wire for heat and a separate for cooling (commonly labeled Rh and Rc on thermostats). So, it seems like you just have one transformer.

Did you measure 24v between the red and brown wire exiting the air handler? Also, common is commonly attached to the metal body of the air handler, so you can also check for continuity between brown and a good metal "ground".

Great diagrams!  They make answering a question like this much easier.


Is using a non-GFCI circuit more risky now than before GFCI entered the electrical code?

Yes, because products are much more cheaply made today than before.

Also they are no longer grounded.

You should see some of the dreck on the market. Follow any of the Youtube videos where EE's do teardowns of consumer products.  It's appalling.

The reason not to rely on "past safety standards you were happy with" is the winner's bias: you're only happy with them because you got lucky.  The dice don't care. Dice have no memory.  Every day they roll again, and every day it's a new risk.  If Russian Roulette works twice, stop doing it!   Now if a $20 gadget increases your odds by like 95%, statistically that's a good play.

People's resistance to GFCI is often based on wild misestimates of cost.  For instance believing you need one per receptacle, at $20 each that adds up fast.   Incorrect, if you apply a little education, you can use them as intended and use one per circuit.


I can't speak to code directly, but generally things like pumps are placed on non-switched circuits to prevent someone from accidentally turning off the pump and then flooding the house.

Imagine a scenario where someone is trying to figure out what the switch does because they can't/won't follow the cable. They flip the switch a few times and nothing happens. There's now a good chance that the switch is in the off position because a) if they're too lazy to follow the cable then it's a safe bet that they are too lazy to remember or care about which position is on, and b) there is no external indication that the switch is off because the pump only runs when it's full of water.


Two long for a comment, Fully agree with shims and glue. I wish they had Gorilla glue when I was building, that stuff works really well as it expands and then gets hard so for some areas that's all that may be needed. The wood needs to be dampened with water first for gorilla glue to work. I have used it on a 2 story home the owner did not want to open the first floor ceiling. I drilled through the floor in several places above the joists dribbled a few drops of water in the holes and once the water soaked in filled with glue, after the glue was dry I cut the tops of the holes where the glue expansion bubbled up. Worked great but you will need to find the joists. There should be a joists because 24" would be the max spacing. My only other guess would be a change in direction of the joists.


What is the best way to retrofit an underfloor heating system in a concrete slab?

If you have sufficient ceiling height, you could consider laying a new floor over the existing floor.

I'm assuming that since the bungalow needs refurbishing, then there is unlikely to be any (or at least sufficient) insulation under the existing slab, so you'd need to insulate under any new underfloor heating - no point having the sub-floor sucking half of the heat out of you new underfloor heating system! Unfortunately, that means that you could easily be looking at 100mm (or more) on top of the existing floor by the time you've accounted for the insulation and screed.

That in turn will give other issues to look at. Doors will become too low. Windows could need to be re-glazed with toughened glass if they then fall within the limit on distance from the floor.


How to raise a wooden floor to same height as adjoining concrete floor before carpetting?

Plywood to build up the wood floor height is an appropriate way to address this problem. For use under carpet some regions may allow use of other products for this purpose such as particle board but plywood is still the best.

Installation of the plywood also gives an opportunity to firm up the floor and work at eliminating any possible squeaking in the old floor. It is best to screw down the plywood into the original floor joists. You can probably find where these are by looking where the old boards were nailed. It can be handy to apply some masking tape to the bottom of the adjacent walls and marking the location of the joist center lines so that after you lay down the plywood it is easy to locate the joints and snap chalk lines across the plywood for a screwing guide.

You may still need to do some special work at the plywood to concrete transition zone because there may still be some minor height variation after the plywood is installed. This can be handled by troweling in a layer of an appropriate floor leveling compound and feathering it out away from the transition zone.


How should I install the post for a mailbox?

Years ago, growing up on a rural farm in the midwest, my father solved the drunk driver mail box problem. He did this after drivers and snowplows took out the mail box several times.

He placed the mail box on a long arm that was cantilevered over a swivel post 10 to 12 feet off the side of the roadway. The design of the swivel post was such that the mail box arm would self return to the normal position if the snow plow would go by and gently push the box out of the way. On the other hand if a driver came by and made a direct hit on the box it would swing 90 degrees and latch into that position till one came to release the catch and let it return to normal position.

The "return to normal" mechanism worked by having springs pull down hard on the swivel part which was mounted against a V-groove seat on the post.


Most things we build are rectangular, and rectangular structures are prone to racking, which is illustrated in this drawing of a deck, but the same problem affects your rectangular shelves:

As you see a structure can collapse due to racking if the joints flex without tearing apart.

There are various ways to counter racking.  Other shapes, like triangles and trapezoids, are not prone to racking.  In the picture, by adding knee braces, you attach the rectangle to triangles, which are not prone to racking.

Another way is to make joints that are not as flexible, it looks like the vertical boards in the front of your shelf are attached in a way that won't flex and allow your shelf to rack left to right.

Another way to prevent racking is to attach a sheet over the rectangle.  For example, if you attached plywood over the sides of your shelf unit, there's no way it could rack front to back.  The sheathing doesn't have to cover the whole side.  You could add gussets - just a triangle of plywood in the four corners - and make the shelf nice and solid.


4 Wires in Switch Box - Ceiling Fan/Light

The non-live black braided wire is not neutral.  Wires are not neutral simply because a voltage tester doesn't light up.  The non-live black is onward always-hot.  It became de-energized because you disconnected it from supply when you separated it. I trust you did not do that hot :)

Take the blue wire out of service. Cap it off at both ends. Tape the cap down (they fall off single wires otherwise).  That's the only time you ever tape a wirenut.

The LINE/SUPPLY black from the new switch joins the 2 cloth switches.

The LOAD/TO-FAN black from the new switch joins the one unattached wire (red).

Up in the fan, connect the fan controller to red and neutral.


Am I able to replace these water valves on my hot water oil heater?

I suppose you could disassemble the handle and clean things but if that doesn't work then keep reading.
Sure, you can replace a ball valve yourself. Have you ever soldered (sweated) copper lines before? I'm going to guess not.
The biggest worry is in the second picture. If you go to heat up #2 for removal then you will likely heat up #1 to the point of failure.

By doing this yourself you will probably spend more money than having a professional do it since you need to buy:

Propane torch
Solder wire
Flux
Emery cloth
Soldering cloth/blanket
New ball valve

This is really a tough job for an absolute beginner to tackle as I fully expect you to ruin your new ball valve by overheating it.
Another consideration is that you need your copper line to be fully drained of water or else you won't be able to heat it properly. If you do heat it hot enough for the old solder to melt while water is in the line then you risk a small explosion because of all the steam pressure you've built up in the line itself.


Try letting the shower head hang for a few days while it's not in use. This might help "unwind" the plastic. You could even run hot water through it once in a while, while it's hanging, to help the re-straightening process. Next trick would be to remove it and place it in hot water then let it cool while hanging.


Big AC motors (refrigerators, air conditioners, washing machines, and exercise equipment) can create large current spikes when they start up - especially if they need to fill a capacitor as part of their operation.

A GFCI will detect current going out but not returning. Sounds like the GFCIs are working correctly. This is by design to catch a situation where the user of an appliance become part of the ground path, and why GFCIs can save lives. They work by measuring the current leaving the GFCI device on the hot wire and returning on the neutral wire. If currents do not match within some close tolerance level, the assumption is the current is leaking somewhere; possibly cooking the flesh of a human or pet as it seeks ground. A device such as your treadmill may have a current mismatch that is completely legitimate, but incompatible with a GFCI-protected branch circuit.

You will need to plug your treadmill into an outlet that is not GFCI-protected. If one is not available, I recommend contacting a licensed electrician to assess the situation and possibly install a new circuit for the treadmill in accordance with whatever electrical code is relevant in your location.


Often times the best location to place the drain lines along a footing is on the outside of the building structure. This allows collection of the water before it enters the area under the building. It also allows trenching away from the building toward a drain field so there is a place for the collected water to go.

If you do put the piping inside the footing perimeter you may need to also install a sump pit at the down flow end of the pipes. Then a sump pump is installed to move the water to a drain or to pump it outside and away from the building structure.


Fixing foundation crack with repair kits

There's two types of foundation crack repair kits, one of them is an expanding foam type of sealant that fills the crack and prevents moisture intrusion. This will prevent water from getting into the basement, crawlspace, etc.... The other type is a bonding adhesive that actually bonds to the concrete and makes a structural repair while also sealing against moisture. Best bet would be to consult a structural engineer, they can recommend the best way to repair it (Even if you do it yourself), the repair kits are $100-800 depending on the size of the crack, with the bonding agent kits being more expensive.


How to mount TV to basement wall under stairs?

As you can see there was apparently already a TV mounted there beforehand.

The person who installed the dual speaker assembly cut off one of the studs and this could be of some concern. You could try to anchor that stud to the side of the stair support to make the stud more secure. Alternatively you could screw a flat 2x4 down (shown as red outline) on top of the lower plate just under the speaker assembly. Then a second flat piece of 2x4 depicted in the yellow outline could be screwed to the added red piece and into the stub of the stud above. The stud may need to be shimmed out with an appropriate piece of wood cut to size. From your pictures this looks like it would clear the rear end of that one speaker. Do use screws to fasten the pieces as the pounding of nails with a hammer would likely blister the nails/screws that hold the drywall in place. Since the added 2x4 pieces are relatively small it would also be advisable to use some construction adhesive to glue the pieces together before screwing. Once set the glue will make the assembly much more solid.

So as long as you put the sturdy mounting screws for the TV bracket into the studs in a proper manner (i.e. predrill with the correct diameter pilot drill) to prevent splitting of the studs you should be good to go.


How can I fill a hole in wood so that it can be redrilled?

Wood filler alone may not fill the entire depth of the screw holes.  I would use a piece of dowel, toothpicks, golf tee, or a carved piece of wood covered in wood glue and fitted tightly into the holes.  Using the wood and glue method will give you a nice dense fill so the new screw will not split the remaining original casing.


Most likely, there are holes in the side of the shaft. Put the wires through the holes and tighten down the ring to hold it in place.


Don't replace the other two switches.

You'll only muddy the water, in fact, I would rollback to the earlier 3-way.

The root problem is that previously, someone replaced the 3-way switch and they did a bodge job of it.

A 3-way switch is supposed to have 2 traveler terminals, going to 2 traveler wires, and a common going either from supply or onward to the light.  In either case, there may be 2 wires on the common - either carrying switched power onto a second ligt, or supply onward to other points-of-use.  You know, like the other two switches right next to it.

Ideally, instead of 2 wires on the common, we like to see pigtails, because  they're easier to understand   and harder to mess up.  However, very likely, the  last guy found the splice had been done right on the switch - one on the screw, and the other on the backstab associated with that screw.

And he didn't know what he was doing when he hooked up that 3-way.  Either he got the wires mixed up... or he got supply and travelers correct but accidentally put the "onward power" onto one of travelers.

If you have any other switches in the area that ought to control this light but don't work or only sometimes work, then more likely the former.

The usual mistake when swapping 3-ways is that every 3-way switch puts its screws in a different position. People think position matters, and it doesn't.  Actually, screw color matters.  Travelers are on brass screws.  So I like to mark them with yellow tape (no need to distinguish travelers from each other).

So see if you can correct that problem, least toward the mispositioning of the onward power wire.


Corrosion on copper pipe: Is this a concern?

Clean it off with some wire wool. As far as I can tell, it looks like marking where flux has run and is unlikely to be any serious corrosion that warrants pipe replacement, but the best way to tell will be to clean it off and see the state of the pipe for yourself close up.


How to patch small holes in concrete slab basement floor?

You can use a variety of patch products.

Premixed concrete patch would work.

Platinum patch

Vinyl spackling

For holes that small i would use the vinyl spackling. You can sand it down if you are sloppy in the application.

I would not worry about holes smaller then a nickle or dime.

Clean and vacuum the holes out to insure good adhesion.


Remove blower wheel that's rusted on to motor shaft

Soak the rusted area in a penetrating oil. Wait a day or two. Cut the motor shaft from the motor, drive the shaft out using a hammer.


Mounting TV to wall with multiple light switches/outlets

I'd get a stud finder with electrical finder. They come in handy and give a general idea if there is wire running horizontally/vertically.

I'd stay with the longer screws. The horizontal wire from what I've seen is generally ran a foot or 2 off the floor for receptacles so I don't think you'll have to worry about it unless behind the wall is a kitchen and then it runs between upper/lower cabinets. Hopefully the electrician put on nail plates so if you did go where a wire was you'd know it when you can't screw beyond the dry wall.


How do you wire multiple lights and a split receptacle with an end-of-run switch?

Perfectly by the book.

Neutral is available in the switch in case you ever want to replace it with a smart switch that needs power.

Black is always live and red is the switched live.


A common problem with ranges is the control board relays fry taking out some of the range functionality. I fixed one that just the oven did not work another that everything was dead. I would start here with the range unplugged look at the the control board there are usually several larger plastic covered relays look for damage on the board. since you mentioned the plastic smell it would be a good starting point. I found the parts for 1 range for 50-60$ the self cleaning convention oven was over 200, that was cheap compared to 1300 for a new one. here is a link to a utube video on how to do it. Added, The relays switch both legs of the 240V if 1 leg of the relay fried (the noise and burn smell) you would read 120 to ground from both ends of the element.


How to install a shower curtain from wall to glass edge?

There are rods readily available that are held up by tension, such as this one

The rod is actually made up of two rods, one inside the other. The rod expands in length as you twist the ends. You could bolt a short u-channel to one end that could hold it centered on the edge of the glass.

 Images and links are for illustration only, not an endorsement of goods or sources.


That Duke Energy box is a remote load controller that allows Duke to power down your unit for some interval during times of peak load.  Generally you get some sort of discount for allowing them to do that.

But it's NOT the circuit breaker.  That is going to be in the main panel or a sub-panel.  Trace the wiring coming into the load controller back to the source of the power.


How to stop a metal table from vibrating when bumped

I would guess that it's the long horizontal bars that are thrumming. Carefully drill one or more 1/4" holes on the inside of the tubing, where they're inconspicuous, and fill the tubes with sand or lead birdshot. Seal it up with tape or silicone.

To maintain strength in the bars, position the holes near connection points.


What would cause water to pulse from the faucet?

Sounds like water hammer.  I had a similar issue with mine.  Your local hardware store should carry a device you can install on your water lines that basically has a little expansion volume to reduce the effects of water hammer.  Easy to install, solved my issue.


You have wild-leg delta. But without neutral, you can only drive 240V loads.

Since your service does not contain a neutral wire, you are not allowed to hook up any loads between hot and ground.  The only loads you can serve are 240V loads.

The 240V loads must be connected on a 2-pole breaker (or 3-pole) with hot1 to one throw and hot2 to the other throw.  You cannot do anything with neutrals, except re-mark them with tape to designate them as a hot wire.

If you have a desire to power 120V loads, you need to contact your power company about getting a 4-wire service with neutral.


Sauna has regular plug but pops the breaker

Do not upsize the breaker without increasing the wire size, 20 minutes at this overloaded value is about right for most inverse time breakers. I would put the sauna on a dedicated GFCI circuit since water is usually dumped on the rocks / heating element. Is the name plate value is 17a or is this the measured circuit draw? Since the circuit may have lighting included that could be what is pushing you over the limit, with a 16a draw the sauna could be safely powered with a dedicated 20 a breaker and 12 awg wire.


Is this white powdery substance on a wood shelf caused by flying termites?

If you saw swarming termites in your house two years ago, I hope you had you house treated. If not, they have your home as the food menu.


Do US electrical codes require ceiling electric boxes?

There is no specific requirement for light placement, although there is a requirement that there be some light in a room on a switch. This is sometimes accomplished by having no ceiling light, but having a switched outlet that controls floor or table lamps.

While you do not have to keep the fixture, you cannot remove the box if you leave a live wire in the ceiling. Also, the box must be readily accessible.

One solution is to cover the box with a blank or decorative plate. On the ceiling you could mount a rosette to a blank cover and attach that (so long as you can easily remove it with screws or other means of detachment).

You say the power is disconnected, but it is not clear if that is at the ceiling fixture or further down the line. If you can find the other end of the cable that powers the fixture, you can disconnect it there. Then you can remove the box and leave the dead (disconnected on both ends) cable in the ceiling. I would cap and tape the ends for safety.  You never know when someone might decide to reconnect a wire.


GFCI and Refrigerator and Circuit Breaker

A refrigerator does not have to be on a dedicated circuit, it's simply a convention some builders/Electricians follow.

A ground-fault circuit interrupter (GFCI) trips in response to a ground-fault.  While a standard circuit breaker trips in response to overloads, and overcurrents.

If the combined current drawn of the refrigerator,  mixer, and whatever else was connected, is greater than the breaker rating (for long enough). Then the breaker would trip, but the GFCI would not.

If there was a ground-fault. The GFCI would trip, but not the breaker.

They are two different types of devices, designed to provide different types of protection.


Anything forward-thinking things to do regarding solar panels when putting a new roof on?

I would be running the pipes to a suitable box ready. Just remember to blank them so insects don’t crawl in - slows the flow rate...
And fit, or mark the beams for fixings.


How do I patch up this cracked corner (plaster walls)?

Caulk.

But before you do that, ask yourself what the reason for the crack may be, and if it's a symptom of something more sinister.   Dry rot?  Termites?  Foundation shifting?  Someone with anger management problems slamming the closet doors?

Of course it may be nothing, in which case you can either patch the entire wall from trim to trim, or just dig out the crack, remove as much dust as possible, paint with white glue to seal the surface and put in several layers of common painter's caulk over several days.  I don't recommend plaster patch in this case, because this seam is likely to move again.  You want something with some flex.

If the plaster is starting to separate from the walls, then Bill Wally has your answer over at : https://www.plastermagic.com/FAQs.html

If the crack opens up again, use a more flexible caulk (not just painter's caulk).


Reducing Heating Costs - Old Brick Apartment, Space Heater vs Central

It depends on the type of central heat you have. Gas is usually cheaper for heat. A heat pump is more efficient until real cold weather then it starts using electric makeup coils. Space heating is less safe than central there are fires every year where a space heater gets moved two close to combustible materials like curtains and furniture.
A small room or space can be heated by a space heater and reduce cost but with the larger rooms and keeping the majority of rooms warm I would use the central system even if it is straight electric for the safety.


edge gluing more wood onto butcher block countertops to make them wider?

Maybe you could stand a piece up and create a backsplash on the back side against the wall? Or if you are worried about the glued piece snapping off, put it on the back wall side and glue it there. Thats how butcher block and cutting boards (unless solid slab) is made by the way, they glue pieces together and clamp tight. If you attach tot eh back wall side, you could pre-drill holes and use screws instead of clamps. You have lots of options.


If you use a GFCI breaker, you don't need GFCI receptacles. As long as the breaker provides the level of protection required at the outlet.

Dual Function Circuit Interrupter (DFCI) breakers are reliable.

"Home run" is not a technical term. It may be used to describe a dedicated circuit, where the circuit only supplies a single device. It may also describe branch circuit conductors, that run uninterrupted from the panel to the first device.


How to wire/replace this bathroom light switch?

Turn off the power, and verify that it's off.
Remove the twist-on wire connectors that are connecting the motion sensor leads to the black wires.
Connect the black wires directly to the new single pole switch.
Install grounding conductors to the switches.


Because, as you suggested, the leak is likely caused by the gap between the shower and wall (and not a leak in the water supply pipe) it's a practical impossibility that mold in the wall somehow found its way into the supply pipe.  So, "No", mold didn't contaminate the water coming from the supply line.


This is my idea, but please post a picture of the other switch of that room.


Looking for an alternative lightswitch, push button maybe?

"I am concerned that this corner is going to break off when I drop the
  board into the rail"

first drop in the slate and then after the slate is already installed in the wall cut it


Do unswitched neutral and ground wires need to pass through a transfer switch?

The neutral does not have to pass through the switch housing. Many wiring diagrams will show it passing through because a common conduit is the norm. The switch housing must be bonded to the system ground, your diagram does not show that.


Yes, it means that each hot in a 240 V receptacle goes to one, and only one, of the linked breakers of the 2-pole breaker that serves the circuit.

EDIT

I am answering here while admitting that my knowledge is limited.

The average US household will have two different types of 240 V circuit--three wire and four wire as follows:

Three wire: hot1-hot2-ground. This gives 240 V between the two hots and services loads at 240 V only, e.g. an electric hot water heater.
Three wire: hot1-hot2-neutral. This is no longer allowed in new construction but is grandfathered. The receptacle for this will serve loads at both 120 V and 240 V. Our electric clothes dryer is served by this type from a 30-A 2-pole breaker.
Four wire: hot1-hot2-neutral-ground. This will serve loads which require both 120 V (one hot to neutral) and 240 V (hot to hot).

In the usual US residence each 240 V circuit is dedicated to one outlet. For example, our electric range is served by one 50-A 2-pole breaker which serves only the receptacle for the range.

A continuous conductor goes from one side of the 2-pole breaker to one of the hot slots in the receptacle, and another continuous conductor goes from the other side of the same 2-pole breaker to the other hot slot in the receptacle . (The receptacle also has slots for neutral and ground, and separate conductors connect them, respectively,  to the neutral and ground bars in the panel.)


How to put up a very small barrier on concrete to stop water running past it

Glue-down garage door seal (sometimes called threshold seal) sounds like what you want. A rubber bump.


Replacing middle of circuit outlet with doorbell transformer

I think you're going to find that replacing the box with a two gang box is more difficult that just adding a new one.
Your black wires along with one from the transformer will be wire nutted together. You white wires along with a black wire from the transformer will be wire nutted together. Then connect your grounds.
The single box will be connected to the framing studs somehow. You'll have to get in there with a keyhole saw or hack saw blade to cut the supports. Be careful not to damage the cables in the wall or screw up the drywall or you'll be touching up paint.
There are two types of old work boxes. One has tabs that hole it in place but you have to follow the template exactly or the box won't fit securely. The other type has screws already mounted in the box and is meant to be screwed into a stud. Those, IMHO, are the better ones to use.  See picture below.


8" to twice 6" sounds reasonable.
twice 6" has a little more cross section than the 8", but it also has 50% more surface, so the smaller tubes have a higher friction.  Over all I'd say that the match is close enough that it doesn't matter.


How do I determine the capacity of my generator when it has a separate starting watts capacity?

If you take the running watts that should be enough. The starting watts should be taken into account by the 8250 number. This is assuming every connected load will not be starting at the exact same time.


Is there a way to split a double wall plug into two separate ones?

You may notice metal tabs between the top and bottom screw on each side of the outlet. These short the top and bottom outlets together. One set of black/white wires provide power to both outlets while the other set of wires continues on to other outlets. This why, when you disconnected the second set of wires, other outlets stopped working. The original installer used the outlet itself as a jumper between the sets of wires.

In cases where the two outlets are powered separately (usually when one is controlled by a switch), these tabs are broken off to isolate the two outlets.

If you want to split the feed to a new outlet, one way would be to connect the new wires to the screws on the outlet. This way, the outlet acts as a jumper between all three sets.

However, I'd note that while the "back-stab" connections to the outlet are legal, many electricians here do not use them and do not trust them. The better way would be to remove the wires from the back-stabs and connect the two black wires, together with the new black wire and a short length of wire (a pig-tail) using a properly sized wire-nut. Then connect the pig-tail to the outlet screw. Do the same for the white wires.

Finally, I need to point out that working with mains voltage is very dangerous. You've already admitted that you have limited knowledge of the field. The voltage you're working with can easily kill you. Also, not connecting the wires well could cause a bad connection that could later heat up and cause a fire! I highly recommend you find an electrician or so least and experienced handyman to do the work!


How do I get started with dovetail joints?

Here's a good tutorial on hand-cut dovetails.  There are two schools of thought - pins first and tails first.  It doesn't really matter, it's more about how you were taught.  This one is pins first.

How I Make Hand-Cut Dovetails


The good news: you have all the wires you need

The good news is that you have all the wires you'll ever need here.  The bottom cable and the leftmost top cable carry always-hot and neutral, while the center-left cable goes onward to the other light switch with its travelers and neutral.  What's more important to us, though, is that the center-right cable is a spur to the other 3-way location for the fan, with both of its travelers (red/white) and the black switched-hot, which then goes off into the far-right cable to the fan alongside neutral.

The bad news: you'll need a different timer if you want 3-way support

As you have discovered, most electronic (pushbutton) countdown timers, yours included, are built down to a price, and thus only support single pole control.  There are countdown timers of this style that support 3-way control, but they require that a matching companion switch device be installed at the other location, which just means we have to do a bit more work.

Matching the style of your original device leaves us with one option, unfortunately, though, and that's the Leviton Vizia LTB30-1LZ paired with a VP0SR-10Z remote.  This gives you the classical "pushbutton timer" functionality at the main location that you are looking for as well as ON/OFF operation at the other location.

As to the hookup

Fortunately, the LTB30-1LZ (or one of its LTBxx brethren, depending on the timeouts you want) isn't too hard to hook up, even with the remote involved.  With the power off at the breaker, of course, we start wiring this with the remote 3-way location as follows:

White from the old switch goes to the WH (neutral) terminal on the remote
Black from the old switch gets capped off with a wirenut
Red from the old switch goes to the YL/RD (traveller) terminal on the remote
And the ground from the old switch goes to the green ground screw on the remote; if the dimmer is any indication, you may have to add a ground pigtail to the existing ground bundle.

You can then button up the remote location, and move onto the timer location, which gets wired as follows:

First, the black switched-hot wire in the far-right cable (heading onward to the fan) gets tagged with (preferably red) electrical tape, as we'll need to distinguish it later on
We then move onto undoing both wirenuts of black wires, and combining all the untagged black wires with the black wire from the timer into a single wirenut
The white wire going off to the other switch location gets incorporated into the existing neutral bundle along with the white wire from the timer
The red wire going off to the other switch location gets nutted to the yellow/red wire from the timer
The tagged black switched-hot from before gets nutted to the red wire from the timer
And the existing ground bundle has the green wire from the timer, as well as a ground pigtail to the dimmer's green ground screw, incorporated into it

Once this is all wired up, you can button the box up, turn the power back on at the breaker, and enjoy your new timer!


Connecting string of cafe lights to power source sans outlet

Since that light fixture appears to be wired with temporary use extension cord anyway, why go through the trouble of wiring up a new weathertite box with GFI receptacle and approved weatherproof "in-use" cover (method probably required for code compliant install)?

Keep it simple. The items that I am suggesting are probably listed for indoor use only. I have a similar setup (in a similarly protected location) and have had no problems for years: socket adapter + lamp extension cord.


What to do if paint peeling on bathroom walls?

...what is causing it?

There is a very high probability that the person who applied it did not sand the gloss off of the existing paint prior to applying the new paint (bathroom paint, typically, has a gloss to it).

Do I need to apply any anti-bacterial compound before painting again... ?

No

Do I need to apply any special primer?

Not if you prepare it properly, meaning sand off all unsound paint that is peeling or seems like it might peel, and ensuring all surfaces below the peeled-off paint are also de-glossed. Make sure the wall is smooth, dull, and clean and you can repaint.
Notes-

if you paint over existing unsound paint, it will all peel again eventually
if you patch (or sand through to bare plaster) you will need to prime
if you choose to use a high quality bonding primer (after proper surface preparation) it will do nothing but help.


Why are these receptacles so difficult to plug into?

They are tamper resistant, as indicated by the letters "TR" stamped between the holes. The secret is to insert the plug squarely into the receptacle. The two little doors inside have to be pushed at the same time by the prongs of the plug.


Widening load bearing door 4" & retaining existing header

That 2 x 12 is over engineered.  I'm guessing this is an older house, built when large dimensional lumber was much cheaper.

First, See this question Proper size of header to support new door in load bearing wall?

It looks like you can conservatively get away with 2 2x6's on edge for the header, and some cripple studs to fill the empty space (Ignore text on img) -

I'm still trying to figure out how you're getting four inches in there without moving that wall stud at the far right of the picture.


What parts of a circuit does an AFCI receptacle protect?

Arc-Fault Circuit Interrupter (AFCI) receptacles only provides sufficient arc fault detection and protection in the portion of the circuit downstream from the receptacle.

If AFCI receptacles offered adequate protection for the full circuit, you could install one receptacle and be done. However, NEC requirements for AFCI protection where an AFCI receptacle is used always require some additional form arc-fault protection for the portion of the circuit leading up to the first AFCI receptacle of the circuit.

The means of protection for the portion of the circuit leading up to the first AFCI receptacle include:

Combination-type AFCI breakers (here, no AFCI receptacle is required because the breaker provides sufficient protection for the entire circuit downstream from the panel). Refer to section 210.12 (A) 1 of the 2014 NEC.
Different types of supplemental arc protection breakers or AFCI breakers to detect arc faults in the portion of the circuit leading up to the first receptacle. Refer to sections 210.12 (A) 2-4 of the 2014 NEC.
Nonflexible metallic conduit, MC, or some AC to protect against a fire caused by arcing with flammable materials in the portion of the circuit leading up to the first AFCI receptacle. Refer to section 210.12 (A) 5 of the 2014 NEC.
Metallic, nonmetallic conduit or tubing or MC cable encased in not less than 2 inches of concrete to protect against a fire caused by arcing with flammable materials in the portion of the circuit leading up to the first AFCI receptacle. Refer to section 210.12 (A) 6 of the 2014 NEC.
For individual branch circuits to a fire alarm system installed according to specific requirements in other parts of the code, including being fully enclosed in RMC, IMC, EMT, or steel sheathed cable, AC or MC with metal outlet and junction boxes, AFCI protection is not required in receptacle or outlet form because the entire circuit is protected against arc faults with flammable materials by the metal enclosure. Refer to the listed exception for section 210.12 (A) of the 2014 NEC.

  From the 2014 NEC:

  210.12 Arc-Fault Circuit-Interrupter Protection. Arcfault
  circuit-interrupter protection shall be provided as required
  in 210.12(A) (B), and (C). The arc-fault circuit interrupter
  shall be installed in a readily accessible location.

  (A) Dwelling Units. All 120-volt, single-phase, 15- and
  20-ampere branch circuits supplying outlets or devices installed
  in dwelling unit kitchens, family rooms, dining
  rooms, living rooms, parlors, libraries, dens, bedrooms,
  sunrooms, recreation rooms, closets, hallways, laundry areas,
  or similar rooms or areas shall be protected by any of
  the means described in 210.12(A)(1) through (6):

  (1) A listed combination-type arc-fault circuit interrupter,
  installed to provide protection of the entire branch circuit

  (2) A listed branch/feeder-type AFCI installed at the origin
  of the branch-circuit in combination with a listed outlet
  branch-circuit type arc-fault circuit interrupter installed
  at the first outlet box on the branch circuit. The first
  outlet box in the branch circuit shall be marked to indicate
  that it is the first outlet of the circuit.

  (3) A listed supplemental arc protection circuit breaker installed
  at the origin of the branch circuit in combination
  with a listed outlet branch-circuit type arc-fault circuit
  interrupter installed at the first outlet box on the branch
  circuit where all of the following conditions are met:

  a. The branch-circuit wiring shall be continuous from
  the branch-circuit overcurrent device to the outlet
  branch-circuit arc-fault circuit interrupter.
  b. The maximum length of the branch-circuit wiring
  from the branch-circuit overcurrent device to the
  first outlet shall not exceed 15.2 m (50 ft) for a
  14 AWG conductor or 21.3 m (70 ft) for a 12 AWG
  conductor.
  c. The first outlet box in the branch circuit shall be
  marked to indicate that it is the first outlet of the
  circuit.

  (4) A listed outlet branch-circuit type arc-fault circuit interrupter
  installed at the first outlet on the branch circuit
  in combination with a listed branch-circuit overcurrent
  protective device where all of the following
  conditions are met:

  a. The branch-circuit wiring shall be continuous from
  the branch-circuit overcurrent device to the outlet
  branch-circuit arc-fault circuit interrupter.
  b. The maximum length of the branch-circuit wiring
  from the branch-circuit overcurrent device to the
  first outlet shall not exceed 15.2 m (50 ft) for a
  14 AWG conductor or 21.3 m (70 ft) for a 12 AWG
  conductor.
  c. The first outlet box in the branch circuit shall be
  marked to indicate that it is the first outlet of the
  circuit.
  d. The combination of the branch-circuit overcurrent
  device and outlet branch-circuit AFCI shall be identified
  as meeting the requirements for a system
  combination–type AFCI and shall be listed as such.

  (5) If RMC, IMC, EMT, Type MC, or steel-armored Type
  AC cables meeting the requirements of 250.118, metal
  wireways, metal auxiliary gutters, and metal outlet and
  junction boxes are installed for the portion of the
  branch circuit between the branch-circuit overcurrent
  device and the first outlet, it shall be permitted to install
  a listed outlet branch-circuit type AFCI at the first outlet
  to provide protection for the remaining portion of
  the branch circuit.

  (6) Where a listed metal or nonmetallic conduit or tubing
  or Type MC cable is encased in not less than 50 mm
  (2 in.) of concrete for the portion of the branch circuit
  between the branch-circuit overcurrent device and the
  first outlet, it shall be permitted to install a listed outlet
  branch-circuit type AFCI at the first outlet to provide
  protection for the remaining portion of the branch
  circuit.

  Exception: Where an individual branch circuit to a fire
  alarm system installed in accordance with 760.41(B) or
  760.121(B) is installed in RMC, IMC, EMT, or steelsheathed
  cable, Type AC or Type MC, meeting the requirements
  of 250.118, with metal outlet and junction boxes,
  AFCI protection shall be permitted to be omitted.


According to NEC 2008 can you use non-metallic boxes in framing that transports environment air?

No.
Physically Constructed Ducts or Plenums
This would be the actual tube where HVAC air is moved through.
In a physically constructed duct or plenum, there is no wiring allowed unless it is necessary for the direct action upon, or sensing of, the contained air. Even then, nonmetallic boxes are not allowed.
Spaces Used for Environmental Air, Other Than Ducts and Plenums
This might be the area above a drop ceiling, or under a raised floor.
In this case, only specific things are allowed.

Type MI cable.
Type MC cable without an overall nonmetallic covering.
Type AC cable.
Factory assembled multiconductor control or power cable that is specifically listed for the use.
Listed prefabricated cable assemblies of metallic manufactured wiring systems without nonmetallic sheath.
Electrical Metallic Tubing (EMT).
Flexible Metallic Conduit (FMC).
Intermediate Metal Conduit (IMC).
Rigid Metal Conduit (RMC) without an overall nonmetallic covering.
Surface metal raceway, or metal wireway with metal covers, or solid bottom metal cable tray with solid metal covers.

Again, no nonmetallic boxes.
300.22(C)(2) Equipment
This section does not apply, since a junction box is likely not considered "Electrical Equipment" as far as this code section is concerned.

If you'd like to read the actual code verbiage, it can be found in my answer to this question.
This YouTube Video from Mike Holt on the subject, might also be worth watching.


Should I put in a sub-panel to add breakers to an older home?

I generally like to avoid replacing main panels outright, because it's a big job that is not DIY friendly and starts a slippery slide of red tape. You need the power turned off. The PoCo won't turn back on without inspector sign-off. The city wants 10 other things added to project scope.  With all the rigmarole it'll be a week, mostly waiting on others. The city won't let you live there with no power for a week. They'll insist on a temporary AC power drop and porta-johns.  A subpanel has a much smaller scope by nature.

Since you are remodeling your kitchen, you cannot rely on just the circuits that are there (so many people think that, it's amazing!)  You will need to go full NEC 2017 rigmarole which calls for at least 8 spaces - more if you like the chef!   Mandatory is typically 2 countertop circuits, dishwasher and disposal, range (2-pole), microwave and (optional, but you really want this!) refrigerator on non-GFCI.   However the chef would very much appreciate 1 circuit per receptacle.  Unfortunately the way kitchen appliances are sized, you can't use 2 on the same circuit without a breaker trip. One per recep works the best.

My rules of thumb

If I'm starting anew, I want a 42-space panel.  Why not more?  Because of panel pricing: adding extra spaces is dirt cheap up til 42, then it goes ballistic.  (that's because the old pre-2014 rules were "only 42 spaces allowed" and the market hasn't caught up yet.)

Now if I have a house with a panel already, and it's a competent modern panel, then my viewpoint is "add a subpanel".  At that point I will want 45-55 spaces between the old panel and the new one.  A "space" is what a twin breaker takes up.  After all, you will have 2-6 spaces used up by the breakers that connect the panels.  So if you currently have a 16 space, I'll add a 30.  A 24, I'll add a 24.  Etc.

My brand priorities are: if you plan a generator, then a Siemens main-lug panel. Otherwise a panel in the same lineage as your existing panel (i.e. Siemens for Murray, Eaton BR for Challenger) so it'll use the same breakers... unless it's Square D QO, then give a hard think if you really want to keep spending 50% extra for your breakers. (It's a fantastic panel but pricey).

Double-stuff breakers. Plan to never use them.  If the existing panel is full of em, you want enough new spaces to let them all be singles.  You can't use them because AFCI and GFCI breakers require a full space, they are mandatory in some cases, and are smart in any case.  There are also some "trick" breakers that take a full space.*

Extra spaces are your best friend. I get very nervous in a house with only 6 spare spaces. Many modern conveniences gobble up spaces 2 at a time. You don't want to have that conversation "No, you can't have a whole-house surge/tanning bed/generator/EVSE because there's no space in the panel".  I like to finish a subpanel job with 50% of spaces free.

A couple things to watch out for.

Look at your original panel for something called "Thru lugs".  These are extra lugs typically on the bottom (surely on the opposite of the main breaker) which allow you to attach wires directly to the main bus. (and switched on/off by the main breaker).  This is for extending to subpanels, so use 'em if you got 'em! The wire must be sized for the main breaker.

FPE and Zinsco panels are dangerous firestarters; the problem is the breakers don't trip and the bus stabs start fires.  The main breakers are often alright, so if they have thru-lugs you may be able to use them and simply move all the circuits to a subpanel next to this panel.  You cannot use a subpanel in the normal way (with a feed breaker) because competent FPE and Zinsco breakers are not available at any price; the new ones are worse than the dangerous originals!

If your panel is Pushmatic, and it has thru-lugs, you're all set. Original/legacy Pushmatic breakers and buses are fine.  But like FPE/Zinsco, you cannot obtain competent new breakers at any price: the ones currently in stores are worse than the FPE/Zinscos! But you know, Pushmatic uses bolted bus "stabs" (certainly the safest type) so getting a subfeed lug kit may be possible: an adapter that takes you from a bolted stab to a lug.

The "Rule of Six" aka "Split-Bus" panel. This is a panel that has an area of 4-12 spaces marked "Main Breakers" plural.  One of the "main breakers" feeds the rest of the panel.  In this case, put a subpanel right next to this panel, and at your leisure, move circuits to this new panel.  The endgame goal being to have exactly one breaker in the "Main Breakers" area, which feeds the sub.  Now it's a "Rule of One" panel lol, which removes the safety issue relating to Rule of Six.

* At a "Maker" show I saw a product that warns you if you left your oven on. Raspberry pi, clamp-on CT, and it pushes a notification to your phone.  I said "The app needs a button to trip the breaker remotely." They were stunned at the idea.  I said "Have an electrician replace the oven breaker with a shunt-trip breaker. Signal that with a 24 volt pulse, and SNAP!"  A great example of one you can't get in double-stuff.


How do I remedy mold/mildew that has appeared since blocking off ventilation?

The problem is humidity and condensation. Wet air is heavier, sinks, and the basement is cooler, so then condenses.

You need to dehumidify that air. The easiest solution is likely to buy a dehumidifier and run it constantly in the basement.

Re-opening the cold-air return can help, as it will circulate some of that moist air out of the basement as well.

All that said, this could be an issue with ground water as well. Are your walls/floor waterproofed from the outside?


how to run conduit past/over wide stone foundation

Your bigger problem is running out of allowable bends (or pullable bends between access points,since pulling near the max allowable is a bugbear and often beyond the ability or available tools of DIYers.  You end up humiliatingly having to call an electrican simply for the pull, and once called they want the whole job.

I would consider a conduit body right at the upper vertical bend.

Conduit bodies are 90 degrees, so I would add a slight ~20 degree bend onto the short conduit coming out of the access panel, to tuck it upward slightly, so it is perpendicular to the angle of the outside wall.  Then, when you make your 90 degree with your conduit body, you come down at the correct angle.  That will also mean you face less than 180 degrees of bend through the underground section, still in the DIY-pullable range.


Running a standard receptacle on GFCI line

It may not be higher load levels but a problem with GFCI's and motor loads, my state exemption for GFCI's includes refrigerator and freezers. If the refrigerator is the first outlet in your kitchen small appliance branch circuit a GFCI outlet can be added to the next outlet and be legal with NEC2014 code. I am out of town and do not have my code book but there is an exhibit showing the refrigerator as the 1st outlet and the rest as GFCI protected on 1 of the 2 small appliance circuits required. I like the refrigerator on its own circuit but it is code to put it first or last on one of the 2 required 20a circuits,,, if not first expect to loose a lot of food, In my professional opinion.


Replacing a split tread on an old staircase

If the tread is loose enough to close the gap by tapping it with a hammer you may be able to glue it .If it is loose take two 3/4x3/4 inch boards that are as long as the crack.Drill four holes thru both boards big enough for a 10-24 screw.With some dry wall screws attach the boards to the tread on both sides of the crack.Apply some gorilla glue to the gap. Using the 10-24 screws draw the gap closed, allow the glue to dry, remove the 3/4" boards.Sand any glue squeezed out.


What would cause a toilet tank to intermittently leak into the bowl only when half-full or more, even after a flush valve replacement?

All I can think of is you are developing a siphon between the tank and the bowl. How high does the water get to the top of the overflow? The overflow pipe is the one that sticks up in the tank.

I would try to set the float level (what ever kind of float it has) such that the water in the tank is an inch below the top of the overflow pipe and see what happens.


What is this thing that holds widespread bathroom faucet handle to sink? How do I tighten it?

This is a faucet that is designed to install from the top only.  Price Pfister calls it Top Pfit.  The piece you have pictured was probably over tightened, bent, and popped off.

Update: It looks like the old name for this was "Twist Pfit" back when they used it for bathroom pfaucets.  Top Pfit seems to be a new name they use for kitchen pfaucets.

It works like a toggle bolt.  It lines up with the pipe to slip into the sink hole then it flops down to a horizontal position where you use a nut or screw on the top side to tighten it.

If you remove the handle from that side valve, you should be able to figure out what to turn to make the carrier with the studs on the side move up and down.  Once you figure it out, the toggle will need to be bent back into shape and snapped back in place.  DO NOT over tighten the valve once you figure it all out.  You can use plumbers putty or even silicone if you are desperate to hold it in place semi-permanently, but over tightening will only get you back to where you are now.

If you look through the PF site, you might find some installation instructions close to your faucet if you need any help, but the design may have changed slightly over the years.

Pictures from found install manual:


We ran our fridge with the water disconnected for years without any problems.
What does the manual say?


You are generally not allowed to use backstabs with 12 gauge wire.   If solid wire is falling off the screw terminals, tighten the screw a lot harder.

If stranded wire is falling off the screw terminals, a lot of people have trouble with that.  There are techniques which help, like twisting the strands as you shape them, and making sure you are hooking in the clockwise direction.  But here's another option.

This link here mostly compares screw terminals to backstabs.   However, it mentions a third type, which they call "screw and clamp", and UL calls a "screw actuated clamp".  That's the one.

Instead of a backstab, it provides a hole (often, 2 holes) almost immediately behind the screw.  You loosen the screw, stick the wire in the hole and turn down the screw tight. The screw is threaded into a clamling plate, which squeezes down on the wire, clamping it firmly.  Check the listing on each outlet but generally they are OK for stranded wire.

Last time I priced these outlets, they were in the $4 range rather than the 75 cent cheapies you can also get.  Of course they are a much higher quality outlet throughout.


Best paint (not spray) for outdoor plastic?

Krylon has a brush on for plastic paint in limited colors. It's their fusion brand.
I have no vested interest in this company and the picture is from there web site.


If you run a carbon brush motor on the metal springs, you'll destroy the commutator (part where the brushes contact the rotor.)

A GOOD hardware store or hobby shop may have brushes in stock you can purchase today, rather than awaiting delivery. Otherwise, if you are desperate to continue, buy another dremel (or similar), rather than destroying the one you have and THEN buying another. Either way you'll buy one, but one way you have two after your brushes come.

It's also a good idea to buy a spare set of brushes so you have a set on hand the NEXT time this happens - when you install them, order another set of spares - that way you never have to wait for delivery to get up and running again.


Why does my photo sensor activate during the day?

Old photocells do age.  Sort of by convention, they are often designed to fail "on". For instance most street lights and discharge loghts use $15 replaceable hockey puck photocells, designed to fail "on" so city staff can distinguish a failed sensor from a failed bulb, and go up in the boom lift with the right part.  The manufacturer will happily sell you a special model designed to fail "off", if you really want that.

New photocells have a different "problem".  They have a microcomputer and a clock, and are able to observe light levels over 24 hours and "learn" what night and day look like.   This makes them resistant to shadowy locations or slow accumulation of dirt.  However they also need 24-48 hours to get acclimated, and if you cut power to them, they may forget and have to learn all over again.

That last bit is important because some people like to put their photocell lights on a switch or mechanical timer too... their modern sensor will never perform right for them.

The transformer is probably solid, the sensor not so much.  You also have to watch voltages, you need a different sensor on the 120/230V versus the 12/24V side.  You may be better off bypassing the sensor on the transformer, then using a modern photo sensor upstream to switch the entire system on and off.


How do I fix a stuck toilet tap that hasn't been turned in 3+ years?

Unfortunately there is not going to be any "trick" that is going to make this easy. Corrosion or mineral deposits may have bonded some of the moving parts. There are basically two ways to attack this problem. Either use brute force or attempt to disassemble the valve. Before doing either, be sure to locate and check the operation of the main water shut off that feeds this toilet. You want to be sure you can turn off the water if the jammed valve in question leaks, needs to be disassembled, or removed/replaced.

Personally, I won't mess around with an old valve for long because a new 1/4 turn ball valve replacement is cheap ($4 - $7), and easy to sweat in place with a new feeder/riser tube or flexible Stainless steel hose to the toilet.

Let's try operating your frozen valve. The brute force method is simply using a pair of pump pliers or a medium length monkey wrench on the handle. Get a grip on the thing and try to open it using the leverage and length of the pliers etc. Applying enough force with a long enough handle will either move the valve or break the valve handle. Assuming you are able to get the thing to move,  the next step is to check it for leaks and see if it will close tightly again. Often, they will not close completely as the seats may be damaged or debris is stuck inside.  This is were disassembling the valve comes into play.  By removing the nut from the valve body on the operating shaft, you can pull the whole cartridge out. Once this cartridge is out, you can inspect it, clean out debris, replace bushings or packings etc and reassemble. If this is an old multi turn valve, it is rarely worth the time and energy to fix it. However, it can be done. This is where I refer you to plan 1, replace it with a new 1/4 turn ball valve.


GPO Has No Power but All Breakers Are On

There may be more than just the three outlets and one has the Ground Fault Interrupt tripped.


You have to remove the white PVC pipe from the strainer by removing the brass nut and pulling down on the white pipe. Once that PVC is removed you need to remove the metal nut which is shown just above the brass nut in the picture.  This will allow you to remove the sink's strainer. Good luck


How can I fix my concrete front porch landing

If the existing landing and porch were poured together, there's probably rebar embedded in both. Breaking off the old landing without disturbing the porch below may be difficult. Plus you will need to add rebar to whatever new step you add and it would be best if it were embedded in the porch.

I doubt you'll have much luck just adding onto the depth and then skimming over the entire thing. Concrete shrinks a little as it dries and I just don't see this staying together for very long, and as soon as water gets in that crack then it's all over.

You may find it easier to highlight the step transition to make it more visible instead of tearing up your entire porch just to add 6" to the landing. E.g. maybe a door mat, some potted plants, or even installing a railing would help draw the eye to the transition.


Proper subfloor for hardwood in a renovation

I would not install the hardwood flooring directly to the 3/4" sub flooring. (BTW at just 3/4" thickness that subfloor is made of boards and not planks as you indicate). A board subfloor is not, in my opinion, sturdy enough to result in a solid floor nor does it provide a decent hold for the flooring nails.

Even if the subfloor was satisfactory you do not want to lay down the new flooring in the same direction as the subfloor. One particular reason being is that any changes in those subfloor boards (cupping) will telegraph right through to the new flooring boards above. Another reason is that a nail row for the parallel flooring can land right on the space between the subfloor boards and have virtually no retention.

You did not indicate how thick your new hardwood flooring will be but if it is some of the newfangled type of engineered material that is not very thick you have all the more reason to not install directly on that board subfloor.

I installed 3/4" tongue and groove hardwood flooring on top of quality 5/8" plywood that was in turn installed over 1 1/2" tongue and groove subfloor planking. The plywood was screwed down using decking screws every 5 inches across the sheets and every 4 inches at the seams. The hardwood flooring was fastened down with hardened spiral flooring nails that were 2" long and pre-drilled through the tongue entry of the flooring. The result was an very solid floor that has no squeaks even after going on 7 years.


What is this technique for matching cabinet veneers called?

Those veneers are without doubt book-matched, but I would say in a very specific method, "Architectural end matching" (End or Butt Matching):

Matching between leaves

P.S. That is some top quality veneering, the attention to detail is almost pure art (the cabinet maker that did that work is an artisan).

This morning on twitter, I asked a few woodworking experts (at least I consider them experts) to take a look at your question:

My initial tweet
@WoodWhisperer initial reply
@MBWPodcast reply
@WoodWhisperer follow on reply
@RenaissanceWW reply


How can I fit patio French doors in a frame that is too small?

It depends on the construction of the door, but if it's a wood door, you should be able to take off 1/4" from the top and bottom without any problem.


How to protect foundation, sill, and siding from moisture (snow)

better than metal flashing and its excellent ability to repel water/moisture is self-sticking rubberized flashing. Although 15 pound roof felt also is acceptable. Either product should be lapped over by the (if any) house wrap and fastened with minimal nails ,etc. I'm not sure about the problem you have in regards to re-installing the clapboards? Won't they re-install with the original fasteners? or is there concern about nailing through the metal flashing?


Yep, that's electrolysis alright. Edwardt is right, you need a Dieletric Union to stop it & it should've been standard practice by whomever chose to do garbage work & guarantee a new water heater very prematurely.

That T & P valve on top might be shot too, which shouldn't be there anyway & was only used as an elbow. If it's from the same guy or firm that did the insulation, then find a new guy or firm...they're absolutely horrible & not even up to hack level work.


Bathroom Switch (Light/Fan) 3 Black Wires? GFCI?

Hard to tell for sure, but what it sounds like you have is:

A common hot wire going to both switches. That is not always the case, because you could have two different circuits, one for each switch. But more typical is what you have - power for the 2 switches coming in together (possibly chained to the GFCI outlet you mentioned, but can't tell for sure - and it doesn't really matter unless there is a problem).

Each switch then has a single wire going to a device (light or fan). Those wires are switched hot. Each device then has another wire coming back - that should be the white neutrals you see wire nutted together in the back of the box.

When switches are simple single-pole switches, they are normally marked (different color screws) for hot vs. switched hot, but it doesn't matter. However, for a timer or motion sensor hot vs. switched hot is critical. In addition, many timers and motion sensors and other fancy switches need to connect to a neutral. Fortunately, you have the neutrals easily accessible - just pigtail into the bundle that is already there.

What I recommend is:

Identify the hot and the 2 switched hot wires. That should be easy if you remember which wire is which - if not, you can (carefully!) turn on the circuit and check with a tester to see which of the black wires is hot.
Connect (wire nut) the hot wire to 2 new short pieces of black wire (pigtails) and connect one to the hot screw on each new switch. If a switch comes with a pigtail attached instead of a screw, you can use that.
Connect each switched hot to the switched screw on a new switch.
Connect neutrals to the new switches using pigtails.
Connect all grounds together, including screwing ground wires into the new switches as needed.

That should get everything up & running.


I am removing some Knob and Tube wiring. Can I leave the NEUTRAL wires hanging in the walls?

I think it's very common to leave disconnected knob-and-tube wiring in the walls.  Leaving a note sounds like generally a greate idea, but I didn't understand where you intended to put the note.

I think the most important thing is to label the circuits going out from your distribution panel so it's clear which circuits still have knob-and-tube wiring.  If you know where the active knob-and-tube wiring is (physically), that would be great to document, too.  It will come in handy if you ever consider blown-in insulation.


How to replace just a few boards in hardwood floor

The last board is always the tough one. A trick that usually works is to cut off the lower half of the groove. Now that last board will simply lay down in place.

The problem is then to get it to stay down. For that you may need a few well placed finish nails, set into the board. Then use some putty to hide the small nail heads. A bead of glue along the tongue may also help to hold it in place.


Greenville County, New Home Electrical Grounding Requirements

If you have more than a single panel, such as a 400A (class 320) meter that feeds two adjacent 200A panels, a single grounding electrode conductor needs to connect the two panels to the grounding electrode. Other supplemental electrodes such as an additional ground rod, concrete encased rebar, building steel, water piping, are not required to be connected all to that single conductor that goes to the primary grounding electrode. Supplemental electrodes can be connected by a continuous conductor or irreversible tap connection to the primary grounding electrode conductor, but it is not required to be connected that way.


What can I do with vinyl tile where the floor edge is open, like at a descending staircase?


Curtain drain in the crawl space - Part 2

OK Peter, next steps are easy compared to what you have done already. The first step is going to be install your foundation grade water proof insulation to the walls, from footer to the top. This comes typically in a sort of tongue and groove panel. Clean the excess dirt etc. off the walls and apply the mastic, then just stick the panels to the wall.  Depending on what brand you buy, check with the supplier's recommendations for proper installation techniques.  They are all pretty similar however. Since you are installing it in a crawl space on the inside of the wall instead of the outside, getting a complete water proofing layer of the mastic is not that important.
I would highly discourage you from using the old spoils as backfill. You mentioned it was a clay base which is very poor for fast drainage. Please use the stone and gravel as I described in your last question. This method will assure you very good drainage. If you buy the drain tile (flex pipe) that is prewrapped, that will save some time and frustration. So, second step is to install your tile, and couple it through the foundation to your existing system.  Complete your backfill, level out the area best you can then start your plastic vapor barrier. I would use a 6 mil minimum.  Be sure to carefully tape all seams and neatly fit the plastic to the walls and tape it.  The idea is to create a good vapor proof cell, keeping moisture out of the crawl space.  You may consider some ventilation for summer season and closing said ventilation during the colder, dryer months.  Sounds like you are well on your way. Don't short cut now, you got a lot invested.  Good luck.


How do I make pavers stop shifting when I walk on them?

Sounds like you need a firmer subbase under your sand to spread the load across a wider area.

I would follow the same procedure as for laying a wider area such as a patio.
It seems like a lot of effort for a small area like the one you have but unless the ground underneath is already very hard and level, the pavers are going to settle unevenly and/or slide horizontally.

Lay a subbase made from a mix of aggregate sizes several inches thick. This type of aggregate locks together nicely and spreads the load across a wider area so no single paver sinks more than the others.
Compact using a plate compacter (tamping down with a large piece of timber or a cinder block would be ok for small areas).
Excavate around the edges and bed the edge pavers in concrete. This prevents the edges of the subbase and sand from crumbling away. Make sure to "haunch" correctly, as shown in this great resource for paving projects.
Lay an inch or so of sharp sand on top and level it off.
Finally, lay the rest of the pavers.


Are you sure about the load bearing? It may sag if you are not careful...

Anyway either replace the post completely or make a replacement bottom section and support the rest of the structure - acrow jacks work well for this type of thing.

This is one example of a supplier of acrow jacks - many others... :
https://www.scaffolding-direct.co.uk/new-size-3-acrow-prop-2-4m-4m/


My cold water valve Seems to have a cap. Is this normal and how can I remove it?

It has ridges on it so try twisting it counterclockwise with some adjustable pliers or channellocks.


Small gap underneath garage's concrete slab on one side that needs to be filled

With the small area and it being on the edge just pack it with dirt. We fill in voids under sidewalks and with sand   Water works well to help the sand flow and provides a solid base where there was a void. , in your case get some dirt and a metal “post tamp” and pack the dirt in by hand it won’t take long then back fill.
On the edge with nothing to trap the foam it will expand and just make a mess, yes I have lifted slabs yes I have used poly and grout.
What is a post tamp, a steel bar that has a round flat end and a flat rectangular blade on the other end used for packing dirt in small areas like you have.


Can I connect a 1-3 adapter to a 12/3 extension cord?

So long as the total draw of all devices plugged in remains below the amp capacity of the power strip, the extension cord, the permanent wiring, and the breaker, you'll be fine.
I believe the admonition against plugging in a power strip is that

You are not allowed (by NEC) to use an extension cord for permanent wiring. i.e. if you need an outlet on the other side of the room for your entertainment center, you should have one wired in, don't run a cord across the floor, around the walls, (especially under a carpet!), whatever, to provide more-or-less permanent power to another location.
A power strip will allow you to plug multiple items in at the same time, greatly increasing the chance of overloading the circuit. If you plug in your miter saw, table saw and router into the power strip and you've got 3 people, each using a tool, you'll very quickly overload the circuity. The breaker will pop, but you could cause damage to the strip and/or extension cord before it does.

If you're using the extension cord as the only supply of power to the shed, and you're planning on leaving it plugged in all the time, that would (I believe) constitute a permanent installation and is banned.
Most importantly, if the cord is stretched across the lawn from the house into the shed, it'll be in the way of the lawn mower. It doesn't take much imagination to figure out what could go wrong there.
If you roll out the extension cord to plug in a fan and a radio while you're out in the shed gardening, then you roll it back up and put it away at the end of the day, then you shouldn't have any issues with the extension cord or with the temporary use of a power strip (to enable plugging in two reasonably low power devices).


How do I design a home air filtration system?

A filtered fresh air supply(intake) would work for this.
You can filter the air in your living space all you want, but any leak or opening could allow dirty air to leak in.

If you filter outside air and blow the filtered air inside, your living space will be very slightly pressurized. Then any leaks would just be your clean air blowing outside, not the other way around.

An air filter with inlet and outlet ducts would be optimal for this setup, and set up the filter inlet to the outside.


Replacing old fan switch with no ground terminal

You'll need to do a bit of digging and wirenut a pigtail on that ground, but yes, that is a ground and should be used to ground your switch, as well as the box if it isn't already hooked up to said box.  All metal things associated with a circuit hook up to the circuit's ground wire, by the way, so you can still hook onto it if it's grounding something "down the line" -- as long as all the cables coming in are connected to it, all the downstream boxes and devices will still be grounded.


All paint finishes will harden over time, so yes.  However, thicker coats of paint take longer to cure.

You used latex paint - this is a softer film surface than alkyd paints.  For this reason, I prefer alkyd for kitchen cabinet doors, although latex paint can be applied successfully if it is built up in thin layers.

Rather than applying another coat of something on top of the paint, I suggest leaving the cabinets to cure for a time.  Once the paint has cured then you can determine if the finish is hard enough (durable enough) for your environment.


What should I use to fix chips in veneer plaster?

I'd use veneer plaster. Your instinct about joint compound and spackling is on target, and you might get Plaster of Paris to work if you get the mix perfect - but why bother.

My guess is that the people you've been talking to at hardware stores either don't have a clue what you are looking for or want to direct you to something in stock.  I'd check at a building supply store (you might get lucky at a big box store, especially if they carry blue board) that contractors in your area use.

Veneer plaster is extremely uncommon in my area, and I can get it when I need it from any of the big chain stores (although I usually have to order it - they never stock it).


How do I connect a C wire to an Utica PEG112CDE steam boiler?

The device labeled "PS-802 ELWCO", is a low water cut-off. The "C" terminal there, is not the C you're looking for.

I believe the white wire from the transformer, is what you'll want to connect your C wire to.  I'm not 100% confident though, since I'm not that familiar with this system.  You may be able to contact the manufacturer for confirmation.


I used the same type of epoxy paint for a basement floor:

Rust-oleum EPOXYSHIELD Garage Floor Coating

There are a lot of different versions as well as professionally applied products. If you want to do it yourself:

Concrete, Basement & Garage Floor Paint at The Home Depot


How do I hook up the wires for my double oven installation?

You will need to replace the wire from the electrical panel to the junction box.  Your new oven requires a neutral (white) wire to power some 120v electronics in it.  Your existing wiring doesn't have that - it just has two hot wires for 240v.


Plastic tailpiece on brass bathtub drain?

It's probably nylon, but it's all fine. Almost every concealed drain uses plastic of one type or another these days.

Those fittings are all compression-actuated. Often the entire trap is also so it can be disassembled for cleaning when needed. Don't use caulk or putty. Tighten them about as tight as you can get them by hand (unless you're a bricklayer).


How to seal molded plastic shower when repainting

The seam between the surround and the wall should be sealed with caulking. You could repair and paint the wall, then use clear caulking at the seam, or repair the wall and seal the seam with paintable caulk then paint. Your choice.

Use a high quality paint and ensure adequate ventilation and no mildewcide is necessary. If you must use it, add it only to the topcoat.