Can I install storm door on the door frame?

A little more info is needed to give any good answer. I can see what would be considered "brick mold" looks like it is extruded aluminum. The frame that you point to looks like it could be painted wood, but the angle at the top tells me it may not be wood at all, or perhaps it is clad in aluminum ??

Typically the storm door jamb screws into the face of the brick mold, just as you may already know. If the surface you point to is painted wood, the storm door jamb can go there, provided there is enough room at the door handle to not interfere with the operation of the new storm door and likewise the original door.

The angle at the top I referred to earlier may complicate the storm door jamb install.


Replacing a PIR light switch with a timer switch

Switches normally just "make or break" the hot lead. Neutral conductors should never be connected to switches except for PIR wall switches and many wall timers. They need to have a neutral connector.

So you should have:

1) constant live hot wire (normally black in USA, but you never know without testing)

2) switched hot wire that delivers switched power to the load (I use red for that, never know...)

3) ground wire (green or bare)

4) Neutral wire (normally white...)

Carefully test, you should be able to identify.


How can I raise the floor of a sunken room level with the surrounding floors?

Without pictures, if there's floor joists/subfloor under the carpet/hardwood/vinyl, etc., it sounds like it would be as simple as just "framing it in". In other words, you'd just add some 2x4s on 16" centers (with top and bottom plates - kind of like a 2x4 wall that is just placed horizontally) that would raise it to the level you want. Note that 2x4s are only 3 1/2" wide, so you'd need to add 2x4s then some 1/2" plywood on top of that as a new subfloor. Then you could finish that with a floor covering like vinyl, carpet, hardwood etc. You'd need to make sure the new "floor" of 2x4s/plywood (or even 1/2" osb) matched the level of the floor you're trying to match. You'd need to make sure you secured the 2x4 addition with toenailing or buy some angle iron to nail into the side of the 2x4s, and then to the floor. But this is all based on if the floor that's there is made of wood. It would be best if you could verify the location of any joists below the current floor because it's best if you nail the new 2x4s to something solid.

If it's a concrete slab, you could do something similar but would need to use treated material so it doesn't rot, and secure it with concrete anchors.


X-brace the structure (under the raised deck of the "fort" part) so that the posts work together to BE a structure. Run opposing diagonal lumber from the bottom of one post to the top of the one next to it, and vice versa. At that point your posts should not be bending at the attachment point, so they should stay put just fine.


how to take the sheen off baked high gloss surface

One thing I use to prep surfaces is scotch bright pads. The green ones are what I use most often they conform to shapes and really take the sheen or gloss out with very little effort. They have red that is    Heavier or more corse or white that is finer but green works quite well for irregular surfaces.


What determines if a plaster can be floated or can only be sanded as the final smoothing step

Yeah, after trying this in practice, this floating 101: you can't bring out aggregate that's much finer than your float's sponge. The max 200um stuff turned out to be some lawyerly spec (as in them not getting sued if someone finds a spec of sand in it); in practice it's as fine a flour or even finer (perhaps close to toner dust). There isn't any float in the typical hardware store that has a sponge that fine. You can "float" it of sorts, but you're not really bringing out the aggregate, just leaving impressions that match the sponge's pattern. You can surely do interesting decoration this way, but it ain't floating.


Should I perform annual maintenance on our heating boiler?

The oil boilers I'm familiar with should be inspected and tuned annually.

Many newer gas boilers need  preventative maintenance only once every two years.

I suspect pellet boilers want attention every year, but that is a guess.


You should get a batch mix for this so that you can continuous pour it from end to end in a short period of time. This is the best way to assure a uniformity and even drying time for the whole slab. Mixing in small batches often ends up with one end ready for finishing when you are still messing around with mixing at the other end.

When you get it all poured from a batch truck you then get to concentrate fully on on the troweling and finishing aspects and coverage if needed due to too hot or too cold of weather.

Another thing that demands close attention is to ensure that the wire mesh gets pulled up into the center thickness of the slab as it is poured. Too often it gets pushed down to the underlying fill sand/gravel where is does no good. I have seen this be an even greater problem with a small mixer process because many wheelbarrow trips across the area keep pushing down the mesh and it gets neglected in the due course of going back for another load at the mixer.

Lastly why not put at least some re-bar in the slab. It is a small cost adder to provide much greater strength to the slab to keep it in one piece.


Why is the bathtub water backing up into the shower?

The rate of flow and effective pressure from the bath is more than the drains ability to drain. This is normally associated with a clogged drain but if you say it's clean. The drain problem is somewhere after the pipes run from the shower. I had that problem previously and it ended up being roots in the drain.
If the shower flows right after you let the water out then there is a blockage close by, but I would guess that the shower only gets water after a few minutes.


I have a sump pump that I use with a garden hose. It works great but has a slightly reduced flow capacity. If that size works for you, use it. My greatest concern would be exposure of the pipe to the cold climate. If it freezes, it will not flow water. The smaller pipe (hose) will put more "head" on the pump but should not cause any harm to your pump. As far as cutting a hole to the outside, why not hire someone or rent a drill that can "core drill" an exact size hole to the outside through almost any wall thickness. It will make for a neat and clean hole with little cleanup needed.


How to lay concrete block without squishing all the mortar?

Brick laying is an art form. It takes a lot of time to get the technique down. Professional masons make the process look much easier than it really is.

One thing that can help is to buy a pre-mixed mortar instead of trying to make your own. It should have a better consistency than what you are using. There are also many different kinds of mortars. A type M or type S mortar would be well suited for putting in a retaining wall.

Type M mortar is the strongest on the market. It is used most when the wall you are building is below grade, and has the best compression strength and is much less likely to squeeze out than other mortars when you are using heavy block. The downside of this kind of mortar is that it is actually too strong for most kinds of concrete block. If there is any movement in the wall, the block is more likely to crack instead of having it crack in the joints. This kind of mortar should never be used for standard brick.

Type S mortar is similar to type M, but it is not quite as strong. This is probably going to be the best type of mortar to use in your application. It is still very strong, but it is a little easy to work with. When using this kind of mortar, you want to make sure that you don't stack too many courses of block in a short time period since having too much weight on the block would squeeze out the mortar.

If you are going to lay brick over the top of your wall, then type N mortar is the way too go. It is still fairly strong, but not so strong as to destroy the brick if the structure is removed. There is a much better chance of being able to reuse the brick later on with this type of mortar compared to type M and type S.

There are also other types of mortar, but those types are generally not well suited for outdoor use, especially if it is load bearing.

You may have a hard time finding all of these different mortars locally. Type N mortar is usually marked as general purpose, and it is the most common.


Some corners like yours are actually two parts--an inner part that's nailed to the wall framing, and a snap-on cover. You can actually see the inner component in your photo at the top. This arrangement allows for various styles to be used. Generally the inherent tension and friction of the two components prevents slipping like you've seen.

With a wooden block held snugly against the bottom of the slipped corner piece, use a rubber mallet or other tool to gently tap the slipped corner back into place. This would best be done on a warm day when the vinyl is less likely to shatter.

A small screw or rivet in an inconspicuous location, or a dab of exterior construction adhesive behind the cover, will help prevent future slipping.


Can a standard NEMA 5-15 outlet be installed in a round ceiling box?

They do make receptacles designed to fit round boxes, for example a Leviton 1228 (I'm sure other brands have it as well, this was just the first I found when I googled Round Box Receptacle):

Depending in the screw holes on your box, you may also be able to fit a standard duplex receptacle and fit a wall plate designed for that purpose. These act as a wall plate and mounting bracket/adapter for mounting a standard receptacle in the round box.

Finally, if all you need is an ungrounded two prong plug, the easiest option might be to get some light bulb to socket adapter, like these GE 54276:


Should I use primer alone first, or can I use paint+primer on renovated/patched walls?

Not all primers are good sealers for new drywall and tape joints. The new paint and primer combinations are great for covering existing paint, but are not a good substitute for a PVA or shellac/alcohol based primer on new drywall or patches. When sealing new drywall, it is important to seal the pores so latex/water based paints are not absorbed. Once the surface is properly sealed, paints will cover better and color will be more consistent and the finish texture will be the same from painted areas to newly primed areas.

Here is a good article that describes the difference between different types of primers and proper selection.  http://www.finehomebuilding.com/PDF/Free/021161060.pdf


AC condensation line dripping from attic drain and splashing onto drywall

An AC unit will produce condensate all the time, not just when its over a certain temp outside.

Check your AC Unit in the attic.  The Primary AC condensate drain is normally drained to either the main house drain or to the outside via a PVC pipe about the same size as the on draining into the garage.

There is a secondary drain, think an emergency notification that the Primary Drain is clogged.  or not working.  The drain you are seeing in the garage is most likely hooked to the drip pan hanging under the AC unit to catch any leaks not handled by the main drain, or the AC Air Handler sweating in the heat of the attic.   In most areas the drip pan is supposed to be an electrical float system to shut off the AC unit is there is too much condensate in it, as that means there is something going on with the AC unit.

Use the attic access in the garage right next the drain pipe and see if that is the drain attached to the Air Handler itself or the emergency drain attached to the drip pan.

If you see another PVC pipe connected to the Air Handler itself,  follow it in the attic to see where it goes.  If it leads outside, it normally will be draining somewhere near the AC Compressor outside, but might be somewhere else.
If you find it outside, a quick fix is to clear it out using a wet vac.

Long and short Pics of the AC unit in the attic will help diagnose the issues, but most certainly a call to the AC Service Company is most likely a good thing if they have not been out to Service the AC system this year!


What is this symbol, showing a wavy line crossed by an arrow?

I don't know whether the EU assigns a special meaning to that symbol but the wavy line means "AC power" and the diagonal arrow means "adjustable" or "variable". So, given this is a wireless switch, that output is the switched hot line. The outer "N" and "L" terminals are the neutral and hot supply connections, respectively, and the inner "N" is the neutral output connection.


Achoring with Drill versus Anchoring with Spanner

First, just a general note - driving lag screws like the one pictured above into concrete or stone would need an anchor drilled and set into the concrete, and you'd also want a washer. If you don't have anchors underneath, you'd probably want a concrete anchor screw or another type of fastener.

That said, you'll likely be able to apply more torque with a spanner than you will with a drill. The drill will make driving it go faster and easier, but if you're concerned with hold, I'd finish with the spanner regardless. Sounds like all you really need is a square-drive socket adapter:


If I have a basement mixing valve, do I need one at the shower?

A mixing valve at the water tank enables you to store water above the appropriate kill temperature for legionnaires bacteria and then allows you to draw water off the tank at a safe temperature. Most codes state above 140°F storage and up to 120°F draw. I find most people are happy with 130°F contrary to code. If you are talking about point of use(POU) set and forget mixing valves (as in, other then the diverter valve) then the answer is no. The best system design utilizes point of use mixers at every consumer contact point. In that case you would need to remove your central mixer.
Point of use mixing system
from Caleffi idronics journal July 2017
POU Mixing is superior because it eliminates the likelihood of bacterial growth downstream of a central mixing valve.
Central mixing valves are still acceptable because bacterial growth is frequently flushed every time a hot fixtures opens, reducing the likelihood of a colony getting a foothold.
Conclusion
You don't need to add mixing valves at each contact point but if you do you should remove your central mixer. Removal of the central mixer then requires a POU Mixer be added.
Edit
The picture above outlines why you should always use a POU Mixing system when a hot water recirculation system is implemented. The principals are the same but with hot water recirc. The hot water lines never get the chance to cool down below the bacterias happy place and thus are able to grow like crazy. That's also why you generally don't insulate the hot pipe in a domestic hot water system.


How far can a 2x4 or maybe 2x6 support over a 10' span?

I do not know how your side supports are constructed or how you plan to keep it from racking side to side.

Three 2" x 6" set on there side so they are like floor joists, I.E. not laying flat.

One front, one middle one back, use Simpson joist hangers to attach to side support rim joist. 1/2" Plywood decking on top of that to create a shelf.

If you want even more weight capacity overkill make it four joists.

How much weight will it hold ?  There is an online sag calculator you can use https://www.woodbin.com/calcs/sagulator/

It is a garage shelf, if it sags a little over time it is not the end of the world. When it does, Turn your  joists over in the joist hangers so the crown is on top and get a few more years out of them. Or use 2"x 8".


2-4 inch gap between crawlspace slab (floor) and surrounding wall - Why?

Almost certainly for drainage. Carrying any water leaking in from the walls to the sump.

My understanding of radon mitigation would be that this gap and the sump pit need to be sealed from the top and power vented to the exterior. Any underslab drainage on the "basement" side should be connected to the vent system as well.

If you already had a radon mitigation system in place and the company did work this way they are a bit clueless/irresponsible. If you did not have such a system, you evidently need one now.


The item you remember is called Swiss frame clips and still commonly available.

The other usual option is a standard method of attaching large glass objects to walls - mirror clips. Fancy or crude.


What amount of wood defects is acceptable in a lumber delivery?

That is some sub-quality lumber and I'd be very upset as well. It's almost like they dumped their reject pile on you knowing that you might not bulk due to the large delivery fees involved and the trouble you would have to personally return it.

They need to either replace it or accept a return including the delivery fee. I don't know that you really need some document to point at to be able to definitively say that it is not acceptable as any reasonable person would look it and know that it's unacceptable quality.

If they won't address it then I would use what is usable, don't use want isn't usable, set it out for them to pick up, let them know, and if they don't credit it then call your credit card company or bank and refuse/back charge the payment for that portion of the bad lumber


I’d turn off all the electricity by turning off all the circuit breakers, including refrigerator, oven, etc. This will determine if it’s electrically powered or battery powered.
If that works, you can slowly restarting each circuit. If not, start checking battery powered items...room by room.


Should you solid fill a low cinder block wall?

The block will be much more durable and solid if the webs (cavities) are filled with concrete. I'm assuming the blocks are being set in mortar? and not dry set? Mortar can be used as a fill and since the height isn't much you shouldn't see any compromise in strength.   You can float the voids level, but a neater look would be to cap the top blocks with an appropriate and preferred material such as granite.


How do I fill a recurring sinkhole in the rainforest of Hawai'i?

Foam sounds like a bad idea to me for a sinkhole. I've seen them cover old wells with large quantities of foam followed by earth, but your situation is a never ending geological process caused by water flow. Have you read this about the Guatemala sink hole? The article suggests the right way would be to layer rocks. Very large at the bottom and smaller as you go up so that the water can flow through that area but doesn't take the soil with it causing another sink hole. I'd go that route if it was me.


How do I mount a second ceiling light from the same junction box

You could use surface mounted box's and raceway.
You would need one box extension on the existing box, this will allow you mount your pendent and then run a raceway, containing the wiring, to a second surface mounted box.
The examples i linked to are all not the same brand, just examples to illustrate what i am talking about. If you go to the home centers electrical dept you will find a section containing these types of products in various brands, sizes and parts to allow you to configure any type of surface mounted raceway/box's.
Of coarse you will need wire, wire nuts, tools and the appropriate knowledge to work with electricity in order to do it safely.


OK.  A 3-way switch complex acts exactly like a plain switch.  Meaning if you take the two 3-ways and the /3 cable between them, and pretend they're not there, you see what else is going on.

In this case, if you ignore the 3-ways and /3, all that's left is a /2 cable to the top box.  That makes this a switch loop.

Normally, in a switch loop, the white wire carries always-hot * and the black wire carries switched-hot.  Code has two things to say about this:

if a white wire is used as hot, and always-hot is in the cable, then the white must be always-hot*.  Correct that if it's wrong.
A white wire used for "hot" absolutely must be marked with black tape.  This has been overlooked in these boxes, so you should correct that.

It appears the last guy wired the 3-way loop with the white wire being always-hot.  That is fine, but again you need to mark the white wires at each of their ends with black tape.

The remaining wires in the /3 (red and black) are travelers.  I recommend you mark both travelers with yellow tape (readily available as part of 5-packs of colored tape). Travelers don't need to be distinguished from each other.

Then it's easy: On the 3-way switches, the travelers go on the brass screws, and the remaining wire (whatever it is) goes on the remaining black screw.

*The white wire is used for always-hot so a voltage tester will always show it as hot; that means it won't be confused for a neutral.  The switched-hot wire will test as "at neutral" when the switch is off, because it's connected to neutral via the light bulb.


Should we vent our attic for new polyurethane closed-cell spray foam insulation?

All right. As soon as you see a headline beginning with "Losing Their Health and Homes to..." you should know that last thing the author has in mind is making your life better. The article is nothing more than atrocious clickbait. Do not make fundamental changes in your life or your home based on what somebody wrote purely to sell internet advertising.

Now, the EPA article can be trusted. But Margaret Badore, the author of "Losing Their Health...", is citing it in support of her super scary thesis. Does the EPA article actually say that SPF in your home is dangerous? It does not. Does the EPA article say you should be worried about SPF in you home? It does not. What it says is that the EPA is not absolutely certain that SPF poses no long-term danger.

In other news, the EPA is also not absolutely certain that composition decking, gas water heaters, iron nails, and NEST thermostats pose no long-term danger. Citing this EPA article in support of the long-term dangers of SPF is a pure and simple lie.

Badore gives the following evidence that SPF can cause health problems:

  [Mr. Rimel] came down with respiratory symptoms [after visiting] the
  construction site of their new home where a contractor was installing
  spray polyurethane foam insulation.

and:

  A couple in their 30's returned to their home four hours after spray
  foam was installed in the attic [and] almost immediately began
  experiencing difficult breathing, coughing, nausea, headaches and
  watery eyes.

Really. More than half of the text in the EPA article consists of every kind of warning against doing either one of these incredibly stupid things. Meanwhile Badore completely ignores the tens of millions of families happily occupying SPF-insulated homes with no ill health effects whatsoever.

The remainder of the EPA page is divided between (1) we don't know about the long-term effects and (2) removing the stuff usually makes the problem worse.

And the Rimels? Well, they searched out a company to test the site and guarantee its safety. Predictably, the testing company basically condemned the property. The Rimels panicked and removed the foam. It didn't help. The partially finished house had become haunted, for the Rimels and for anyone else who read the super scary test results.

  After months of being unable to find a satisfactory solution, they
  sold the property.

Don't be like the Rimels.


Can I add a second circut using an existing ground and neutral?

If you want two breakers, you can't share a neutral and ground. The shared neutral and ground could be exposed to too much current, because they don't have breakers for protection, only the hot does. An example:

Assuming you've got an existing circuit with a 15 amp breaker and 14 gauge wire, you add a second 15 amp breaker, running a new 14 ga hot, and sharing the neutral and ground from the existing circuit.

You have one load plugged into the "old" outlet, drawing 10 amps. 10 amps comes out through your old breaker and your old hot, the old 15 amp breaker sees 10 amps and doesn't trip, and the 10 amps goes back through your old neutral.

Now you plug in another load to your "new" outlet, drawing 12 amps. 12 amps comes out through your new breaker and your new hot. The new 15 amp breaker sees 12 amps and doesn't trip. 12 amps goes back through your old neutral. Now you've got a problem.

Your old 14 gauge neutral is now carrying 10 amps from the old circuit + 12 amps from the new circuit = 22 amps: thats more than the rated capacty. You haven't tripped a breaker, but you've overloaded your wiring. This is a very dangerous situation.


How to calculate therms usage from oil usage?

Figures, just found that 1 gallon of oil equals 1.35 therms.
Another consideration is the efficiency of the unit.
From a recent energy audit in know its efficiency is 79%.

This means my 100 gallon estimate is 135 therms.
Now to try and guess what the gas bill would look like, based on their charge model is another story.


Brand new shallow well jet pump, noisy and slow

Were I looking for leaks causing the noise & slow fill issues, I would not expect them to bubble out - they would be leaks on the suction side sucking air in. A shallow-well pump sucks water in (practical limit 27 ft lift from surface of water when pumping - theory might give more than 30 but it's not practical - limited by air pressure and how closely the pump approximates a vacuum) and then spits it out under pressure.

Static Water level is 8 ft down - how deep is the well, where is the foot valve located? Does the water level drop significantly when pumping?

Here's my best guess as to your root problem:

What is your priming procedure? It appears that you have a check valve on the input, which will prevent priming the pipe from the prime port on the pump - so you'll have to also fill the pipe from the plug in the top of the Tee before the check valve.

IMHO that check valve is not a great idea, as the foot valve either works or does not work, and the additional check is not helpful, but many pumbing codes are check-valve happy to the point of not helping things.


How can I determine the STC (Sound Transmission Class) rating for my condo walls and ceiling?

I lived in Southern Calif. in the '70s, I'm pretty sure there was no STC standard for multi-family residences at the time. The only requirement was for certain party walls to be fire rated, and not necessarily every party wall. There are publications available that show the STC ratings for various constructed assemblies. You can find an assembly that is similar and get some idea of the rating for your assembly. However, you cannot claim your assembly achieves a certain STC rating unless it is built EXACTLY as the published example. If there is any variation, you cannot claim any STC value at all without having it tested.

Still, reviewing the various assemblies will give you an idea of what needs to be done to achieve a reasonable rating. BTW, much like water proofing, there is no such thing as soundproof, only degrees of sound resistance. Note it is called a Sound Transmission Coefficient. The implication being some sort of sound will be transmitted in all cases.

Perhaps the biggest issue with applying sound treatment to an existing building is your options for eliminating flanking paths is very limited. Even if you build a very effective sound wall, unless you address how the sound can travel through the adjoining floor, ceiling, and sidewalls, it may have only minimal effect.

That said, I applaud your consideration of your neighbors. Doing something is certainly better than doing nothing. But do not think you can blast your audio system with impunity just because your sound treated the one common wall. Effective sound treatment requires addressing ALL the related construction adjoining the wall in common.


How can I hang a shelf off of existing screws in brick wall?

I wouldn't use those screws since you have no way of knowing how they were installed.  However, I would suggest you look into brick hanging clips (use Google to find them). These are made of metal and are designed to grip the bricks. No holes are required. You made need a number of them depending on the weight of your stuff. I have used them to hang pictures on brick walls.


Which qualities should I look for in a driveway sealer for new asphalt?

You're looking for two things: 1) wear surface, and 2) adhesion.

1) Wear surface: There's always good-better-and best in all things. Asphalt coatings are no different. Asphalt coatings are a oil-based product and wear has to do with particles in the compound (liquid). When oil is "refined", it has chemicals and particles that can be used for asphalt coatings, roofing, etc. (How it's refined give you the good-better-and best results. I don't know how to determine which is best, but see item 2), below.)

2) Adhesion: Look for a coating with a "gel base", not a "latex base". Gels flow, coat and adhere better. (Btw, the warranty is longer with gels too. I think warranties are 3-5 years with latex and 7-8 years with gels.)

Btw, you said you have NEW asphalt. Do not coat or seal it until it's "cured"...about 6 months. Follow the directions...clean, apply at correct temperature, etc.


Why don't my CFL bulbs stay on in my ceiling light fixtures?

I have found a vast difference in the quality of CFL lamps. It is possible you have a batch of bad bulbs. Some brands last for years, other several months. I would swap the bulbs so that one room has all bulbs that don't go out. Turn on the light and see if the problem persists. If the lights stay on replace the defective lamps.


Why did my electrician put metal plates wherever the stud is drilled through?

This is excellent practice. These plates help guard against someone accidentally drilling into the wire when mounting things on the wall.


What actually happens if I vary proportions of cement and sand in mortar?

Codes and other guides provide nominal mix combinations that perform fairly in general conditions.

In general, a 1:2 mix will give better strength than a 1:3 mix. But it is quite possible that a 1:0.5 mix might perform worse. Strength comes from inter-particle force transfer between sand grains and also from shear resistance provided by cement acting as adhesive. Thus codes provide known balanced combinations that are satisfactory.

To gain complete control over the properties of a mortar/concrete mix, you must consider the following criteria:

Cement Amount: As a thumb rule, increasing the cement increases the strength. Beyond a certain point, it also acts negatively. Since major force transfer in a concrete/mortar matrix is from sand-sand interaction, excess cement will turn the mortar very brittle since cement particles cannot transfer normal contact force - they are good at providing shear strength. Since cement is expensive, in low-strength applications like roads the amount of cement is less to optimize on the cost.
Water Amount: Generally water content ranging from 20% - 35% (w/w cement) is considering a safe operable range. Lower water content gives low strength and less manoeuvrable mix for flat conditions like road laying. Higher water content is generally used in specific conditions like laying out pile using tremie - where the free flowing nature of mix is necessary. Although high-water also leads to lower strength, there are other workarounds (mentioned ahead).
Sand Amount: A very high amount of sand will make your mix very brittle and weak against all kinds of forces. For M20, M25 etc, general proportion is 1:3. However, for High-strength mix (M35+) its better to go with 1:2 and somewhere about that.
Aggregate Amount: Aggregates have two reasons to be there - economy and strength. They are cheap and provide as a good filler. Very high and very low amounts of aggregate give poor strength but a varied economic solution. A moderate amount is good enough.
Aggregate shape: Generally, increasing crookedness of the aggregate particle gives increasing strength as it gives a higher contact area and better inter-lock capabilities.
Air Entrainment: A high air-content in the mix leads to lower strength. That's why high-strength concrete is vibrated before laying to expel the small air-pockets. A low air content gives low manoeuvrability, so sometimes, 'air-entrainers' (chemical additives) are used to give the desired flowing nature without compromising on changing the water content and consequently the strength.
Additives: Physical additives like 'fine-silica-powder', 'fly-ash' allow cement reduction and provide economy. fine-silica is ... very fine so it goes into the smallest of voids and provides good contact strength by reducing the air content. Fly-ash comes as a general replacement for cement. It is a by-product from thermal power stations and is very cheap. Upto 15% cement can be replaced by fine-silica and upto ~40% by fly-ash. Chemical additives like super-plasticizers do provide a effective workability increase, or even a water reduction at similar workability - thus giving a higher strength mix.


How do I find out the correct pre-charge air pressure for my captive air water tank?

Pressure Switch

I've never seen a "safety cut-off" on a pressure system before, but typically the switching is done by a single box (known as a "pressure switch"). Pretty much all of them (at least from the last ~20 years) look something like this:

The large nut is used to control the pressure (both cut-in, and cut-out) and the small one controls the range between the two.

Finding on and off pressure

First of all, you need a working pressure gauge to be able to do anything, so replace that.

To find the current setpoints:

Run the pump until it shuts off (this is the off pressure)
Open a tap or two, and wait until the pump cuts in (this is the on pressure)

Btw, 95psi is really high. Most homes run 40/60 or 50/70. International Residental Code maximum is 80psi (IRC P2903.3.1). Beyond that, you'll potentially start having issues with leaking toilet valves in particular, but other failures are possible as well.

Bladder tank pre-charge

Normally the pre-charge should be set to 2psi below the on pressure, but if your tank recommends setting it the same it shouldn't make a huge difference.


How can I fix this broken connector piece on my Symmons shower Knob?

Here's a link to the Installation, Operation & Service Instructions (PDF) that contain an exploded diagram of all the parts of your valve.

Click for larger view

If you scroll down you even get detailed instructions about servicing the valve, how to order parts, and troubleshooting for common problems (like not getting enough hot water).


Should backer board be installed all the way to the ceiling around a shower?

I don't believe it's necessary to run the concrete/hardiboard all the way to the top on a remodel application.  Your point about not messing up the ceiling is a good one that people often run in to.

I assume that the drywall that is existing is greenboard or blueboard (i.e. wet area approved)?  You have to think "if it's lasted in bathroom this long..."  I ask because "wet area" rated drywall is better at dealing with mold etc and if it's a moderately modern home then it's likely that code required it's use.  The only other issue (especially that high on the wall) will be if the hardiboard and existing drywall are flush with each other.  Even if they're a tiny bit off the mastic may help make up the difference. If you tape the joint between the two use a non-paper tape (they make fiberglass).

As to bonding tile to drywall?  It's done all the time, especially in kitchens as backsplashs etc. Just make sure you get a good quality tile adhesive.  I prefer portland based w/ a modifier such as acrylic.  I think it grabs tile much better than the cheaper white thinsets.  You may have to mix it from dry but it's worth it.

Best of luck!

Port


You say 8' x 10' deck.

The code requires a deck to support 40 lbs. per square foot. (ICC Table 301.5.) So, live load plus dead load (about 6 lbs. per square foot) equals 46 lbs. per square foot total load MINIMUM.

If the joists/beams are 4' apart, the ones on the edges will need to support 92 lbs. per linear foot and the middle beam will need to support 184 lbs. per linear foot.

A 2x6 spanning 10' can support about 60 lbs. per linear foot. A 2x8 can support 140 lbs. per linear foot.

I'd use 1 - 2x8 on the edges and 2 - 2x8's in the middle.

Now, make sure they're fastened to the posts to support 500 lbs. at the corners and 1000 at the middle beam. (Usually we like to place the beams on top of the posts and then just use a clip to keep the beam from moving off the post.)

Also, if it's more than 30" off the ground, the deck will need guardrails and if it's adjacent to the house, it'll need lateral resistance attachments to the house.

By the way, 2x6 decking can barely span 4'. It will feel springy when walking on it. You could run the beams the other direction, add one more set of concrete footings, and use 2x6 beams (spanning 8', which will support 90 lbs. per linear foot.). Then, the decking will only span about 3'-3". Much stiffer.


What are the pros and cons of sash vs. tilt and turn windows?

I think this probably has more to do with regional building habits than any systematic optimal decision. I agree, what you call "tilt and turn" windows seem to be more common in Europe. In the US (and elsewhere?) a similar style is a "casement" window, although it's not as functional (doesn't open as far and doesn't offer multiple ways of opening).

I have seen "tilt and turn" windows used in the US in basements, since they can satisfy emergency egress requirements. Perhaps they are less common in general use because they are more complicated / expensive? The latching and hinging mechanisms are much more complicated than a sash window, which typically is just held in place by friction.


Overloaded circuit on ungrounded outlets

Not a lost neutral

A lost neutral in an MWBC is easy to test for.   Just remove all loads and plug in two 240V-tolerant loads, one into each half of the MWBC.  (watch it - the appliances may see voltages as high as 240V!) If one leg has higher voltage than 120, and the other has lower voltage than 120, and they total to 240, then you have a lost neutral.

However, from the sound of it, that's not what you have. It sounds like you have a lost hot wire.

Phantom voltage is confusing everything

Also, you are running into a phenomenon called "phantom voltage".   If several wires are run parallel for a distance (like any wires in cables, or cables next to each other), the wires will have capacitive coupling.  If one wire is disconnected/floating, and a voltage will appear on it, induced from the other wires.   This voltage has no strength.  It can move the "needle" of a digital voltmeter; those are so sensitive they will read the phantom voltage.  It cannot move the needle of an old analog meter in most cases.  Apparently, it can dimly light certain cheap LEDs.

Phantom voltage is never full voltage.  It is somewhat less. For instance if your mains voltage is 121 volts, and you measure 109 volts with your DVM, that's not "meauring 120V".  That's phantom voltage.

Phantom voltage means the wire is disconnected between here and the source, and it runs alongside or in the cable of live wires.

It appears your lighting MWBC is inducing phantom voltage onto your outlet MWBC.  That's interesting, because the two hot wires in a MWBC are supposed to be opposed, and you would expect capacitive coupling from them to be equal and opposite.  In other words, to cancel each other out. **I suspect this is because one wire of your lighting MWBC has a wire break.

Tied neutrals

So far, you may be thinking "well, all the evidence I saw of a tied neutral, may just be phantom voltage.” That may well be.  But a tied neutral is a very serious defect.  It can result in that neutral overloading.  And what just happened here?  You plugged in a heavy load, and the circuit quit.

So as you search this wiring, you must separate any neutrals between the 15A circuit and 20A circuit.  If you have any smart switches in the 15A circuit stealing neutral from the 20A circuit, get rid of those.  You can't have that; it's illegal and it will painfully complicate troubleshooting.  Normally I would say distinguish them with tape markings, but they are different sizes so that should be obvious.  It is OK to tie safety grounds, but you say you don't have any.

Follow the dead hot/phantom-voltaged hot back to the panel

Let the phantom voltage be your guide. The wire break is either at the first failed outlet in the chain, or last working outlet.  I'm using the royal meaning of "outlet" to include any point of use, including switches.

One more thing.  The single likeliest cause of problems like this is backstab connections.  Those are uninspectable.  The only way to inspect them is destructive.  Push the release tab if you can, and then twist and pull the wire out. (Never cut. Wire length is precious, but our entire point here is to inspect the side of the wire for spatter and spallation marks from arcing).

If you found tiny arcing marks, you probably found your problem.  Welcome to backstabs.

Like we say, don't use backstabs at all; but if you're tempted to just jab it back in, don't.  The backstab's tiny spring is now weakened, and if used again, will only cause problems like this.  The backstab has 4 springs and cost 50 cents, what do you expect from it? :) Use the side screws.

Priorities

I would focus on fixing the lighting circuit, patrolling for tied neutrals, and then, once lighting is back, focus on the outlet circuit.


Why in the UK would a garden room have a canopy?

To keep rain and dirt off the glass an to offer a bit of shade?

We have an Orangery with a wide cornice around the roof. It does a good job of sheltering the windows.

It also stops a square. flat roffed building looking like a bunker.

Our Orangery look crap until the cornice went on. Then it looked epic!


You don't need a DIY forum, you need a lawyer or a politician. Your landlord is breaking the law. Good luck getting this resolved!


How can I improve this deck ledger and the flashing around my ledger?

Perfect world ... the flashing would be gav metal and create a template (opening) for the vents. Top and side exterior would overlap this flashing top down to DRAIN water (installed as bottom, side, top). I'll mention tar paper here, or peel-n-stick, to underlay and cover any missteps...USE IT.

If...when...you replace the wood, and peel-n-stick the area (bottom up so top overlaps bottom), it will never leak! Your problem is more of a surface issue where the vent is recessed. Fix that and bluff the vent out to make even with the exterior surface, then seal and flash in.

Caulk..and press caulk into any crevises or corners...the outline of the template when finished for a water tight seal.

Don't be scared of the opening, put a hose to it to check for leaks and see where/how you need to repair.


How can I attach closet shelving supports where there are no studs,

A 2x2 glued to sheetrock won't support any weight.

Instead, go through the sheetrock and install a masonry anchor in the cinderblock. Put a screw through the 2x2->sheetrock->cinderblock


Light switch for multiple fixtures feels warm after a while

Unlikely that the switch isn't heavy duty enough. But the contacts in the switch and/or the connections to the wires may have problems. I suggest replacing the switch just in case it is having internal problems. When you do that, check the wires for any evidence of arcing. If the wires are not in good shape, cut off the end and strip a new section to attach to the screw terminals on the new switch. Obviously turn off the circuit at the breaker before doing any of this.


The water analogy is sometimes used to help people when they are first learning electricity.
Water flow (volume of water per time period) is analogous to current.
Water pressure is analogous to voltage.
https://en.wikipedia.org/wiki/Hydraulic_analogy


In many cases a ceiing in an older home if replaced needs to have an attic strongback installed to occomdate the new ceiling.  As a home shifts with settlement of ground and foundation the current strongbacks are compromised.  So when installing ned to old, the old ceiling joists need to be supported.  When the old drywall was removed, the old strongback releases pressure and caused the joists to shift.  So work must be done to the structure of the attic.  It is obvious that the strongbacks and the joists are drooping. Is it the drywall guys fault?  Yes and no.  He is not a structure contractor.  It is the General Contractors fault.  And if the home owner was the GC...it is the inexperience of the homeowner.  When you hire a finisher to repair problems, you have bad results.  In a court situation if you attempt to litigate, the finisher will win the suit as he is there to install the drywall to the existing structure only...He does not have the skills for anything else.


How high off the ground can you place LED lighting?

There is no general formula besides some really scientific ones. It is rather difficult to find rules of thumbs for calculating light in rooms. In your case the illumination levels on your seating area depend strongly on the beam angle of your luminaires.

However, it is both possible to do some calculations by using pen and paper and to do exhaustive simulations using a computer.

For the latter there are at least two free but professional softwares:
Dialux and Relux

While it takes some time to get into it, you can yield very professional results. Both softwares contain a 3D-modeler for your rooms and exhaustive luminaire databases as well as the possibility to import lamp date like IES and EULUMDAT.

To do a calculation by hand, you need to know the FWHM (full width at half maximum) angle and the lumen output of your light source. Then calculate the illuminated area. Use the formula for the base area of a cone (you can find that at wikipedia) from the FWHM and the height of your room. Then divide the lumen output of your source by the area and reduce that value by roughly 30%.
 Then you get the illuminance in lux. If you install more than one of these sources close to each other, you can simply add up these values. 200 lx are fairly enough for recreational areas. For more challenging tasks like drawing, you need 500 lx.

I suggest looking for lamps with a beam angle not bigger than 30°, perhaps even 15° is necessary.

One thing to consider if light sources are far away is the formation of very sharp shadows. And with a multiple of distant light sources the formation of multiple shadows, which can be quite annoying. This can be avoided by a flat light source. But most flat light sources have a wide angle making it difficult to bring the light there where you need it.

One way or another this will be some sort of tradeoff.


You will need to install a NEMA 14-50 outlet for your new stove.  Connect the black wire to L1, the red wire to L2, the white wire to N, and the copper wire to G, then plug your stove in.


Is it a good idea to cap fiberglass batts with blown cellulose?

It's the opposite, in fact: in terms of thermal performance, cellulose is better on the top layer. The reason for this is that compared to fiberglass, cellulose is more dense and more opaque to infrared radiation than fiberglass is. Most attic heat gain is caused by infrared radiation, and convection through the insulation plays a strong role in heat loss. Having a product on the top layer that's denser and more IR-opaque helps to prevent convection within the insulation and slows infrared radiation more.

Cellulose is fire-resistant because of the borates, but by no means fireproof. It is still paper. I've heard of attic fires caused by smoldering electrical work done wrong but buried in insulation. Fiberglass of course is basically fireproof until the fire is so hot that it causes the fiberglass to melt, which is somewhere around 1,100 degrees Fahrenheit. Much less risk.

A superior product compared to both is mineral wool. It's got all the advantages cellulose has over fiberglass (in fact, it's even better), but it's inorganic and thus fireproof. You'd need to install this product in batt form, since it doesn't generally come loose like cellulose and fiberglass. And it is much more expensive than those. But if you want optimal thermal performance as well as fireproofness, it's hard to beat.


How to hook up the C wire from my thermostat to the air handler?

That looks fine.

The gist is that a transformer has two wires with 24V between them.  The R wire goes to one, the C wire is the one which is not R.

You've got a lot of exposed bare-wire 240V power in there; be careful  and shut off every furnace breaker before going in there.   There is likely more than one.


What is the best approach to install crown molding on uneven top cabinets?

I think you have it right.
A mounting block installed at the top of the cabinet face is the way to go. In your previous kitchen the crown molding was top mount. I've often seen that installed with a mounting block or nailer fastened to the back of the cabinet face and the molding nailed or glued to the front of the nailer.
With the issues you described the surface mount crown molding the way you drew it up is the best solution. For extra stability on the nailer you might want to consider building a simple L (actually, an upside down L) mount. Depending on the depth of the offset at the top of the cabinet behind the cabinet face you could fasten a 1x2 so it extends up vertically over the top of the cabinet and then add your nailer so it butts up to it.
Small differences in the height of the cabinets won't matter much and will be covered by the molding. However, you can always use a sander to quickly remove any major differences in height.


Will a 2-stage heat pump cool my upstairs on low stage?

The answer will depend on how much temperature drop/rise there is inside the ducts.  A two stage cooling system means that the heatpump will either drop the air return temp a little bit (stage 1 is running, half cooling) or it will drop the air temp a lot (stage two is running, full cooling). Either way the fan moves the same amount of air.  In stage 1 mode the net effect will be for it to spend more time with the fan on, since to hold say 70F it will have to spend a while pushing 65F air through, vs a single stage system that puts out 60F air which will get back to setpoint faster.  More air circulation (assuming its all a nice 65F) should actually be better for comfort in your restricted upstairs area vs spending a short time blowing 60F air until the downstairs is comfortable, leaving the upstairs without much time to get cooled air.

If the ducts are soaking a lot of the cooling up (i.e. the downstairs is getting 65F air but the upstairs is getting 68F air) then no, the first stage of a two stage unit will not give a lot of comfort and a system pushing colder overall air (i.e. single stage) all the time would be preferable.

In any case (if you get this system or not) most ducts, even in older homes, have some sort of internal damper to control flow to each run/room. These might not be accessible if you finished your basement and covered them all up, but that's for a different question about exposing louvers and patching sheetrock ;-). Further, your vents in each room should have a shutoff (not preferable vs in-duct damper, because it's noisy) which would allow you reduce the airflow to the downstairs rooms. This would be the solution if you find that running the system just doesn't get the upstairs rooms comfortable.  Start by reducing flow to the one or two ducts closes to the thermostat, and continue until your system runs long enough to cool the upstairs without leaving any of the first floor rooms too frigid.

edit: grammar and clarification


Single 14/3 wire for 2 independent switches

Lots of things going on here.

You are getting the weird voltages because you are measuring across all hots. If you measure between any of the wires in your box to the box itself (this assumes the box is grounded correctly) you should get close to 120v.

So yes to your first question, you can use the exact same wiring to connect your dimming switches with a couple of caveats.

Make sure your dimmers and LEDs are compatible. Check the packaging or Google it.
Add a grounding wire. (See Below)
The dimming switch does not require a neutral (common in smart switches)
You are going to have to be careful wiring up your lights. That white wire coming into your switch box is HOT, not a neutral. You should wrap it, and the other end, in black E-tape, to mark it. Make sure your chain of LEDs are wired in parallel with the Red or Black wire as the hot, and what should be a different white wire (probably found in the same box as the other end of the 14/3). If you have more questions about the wiring of the LEDs please post pictures of the lighting wiring or start a new question.

based on the photo you do not need to change any wiring. When adding fixtures to the Red wire, Run 14/2 from this box and continue to each subsequent fixture (you can and should daisy chain). In the box pictured connect the black wire to the red wire and blue wire (blue is the fixture in your pic). Then add the white wire of the new 14/2 to the 4 already twisted together. It looks like there is already a 14/2 running from this box to the other fixture. So you dont need to add a wire, just continue chaining 14/2 to that system of fixtures tying all the hots together and all the white/neutrals together. The last fixture of each chain will only have one 14/2 going to it.


Is there a suspended ceiling tile that allows sound to pass through without reflecting sound?

AFAIK, the insulation in the ceiling is to prevent sound traveling through the floor above. It's not intended to necessarily reduce the sound within the room itself (though it will, to an extent, as it'll be a softer material than concrete or wood and the surface texture will help dissipate sound).


Single breaker, split wire that is inaccessible and one wire not working

If the bedroom power is being daisy chained through multiple outlets, I would physically check the wiring on each one.  I have encountered problems with backstabbed wiring several times.  Last time I fixed something similar for a friend.  Their power was daisy chained through 4 backstabbed outlets.  The third one in the chain was the problem.  It even tested good with a non-contact voltage reader.  It turned out to be an intermittent arcing connection.  I took out all the backstabs and wired them around the screw terminals.


Why have an off position for the heating dial on electric showers?

Note: this answer is based on my experiance in the UK, I do not know if this are the same in the rest of the world.

Traditionally the "temperature" control on an electic shower did not directly control temperature, instead it controlled flow rate. For a given input water temperature and heating power, a lower flow rate resulted in a higher temperature.

Nowadays nearly all electric showers have thermostats to prevent the output water becoming unexpected hot in limited water scenarios, but the control scheme in normal operation (not limited by input water) remains the same. You set a power control to select how much heating power (if any) you want, then use the main dial to control the trade-off between temperature and flow, or in the case of "cold" mode to control the flow.


How do I fix my trim that wasn’t sanded well

I'll take a different tack and assume you're referring to the bumps where the fastener holes were patched. My fix at this point would be to make sure that the paint is thoroughly dry so that it sands well. Then take a random orbit sander and go over those areas again. If you tilt the sander just slightly so as to apply pressure on one edge of the pad  you can sand a fairly small area fairly quickly. You'll have to completely repaint, of course, including any primer coat you may have done before.


Mystery Electrical Voltages in Duplex Junction Box

TL;DR -- find the breaker that shuts that red wire off, then slap the builder with it, so to speak
The builder of your house needs a slap with the NEC.  There are two very clear Code violations here, and they're both things that are trivial to avoid.
First off, the lack of panel labeling isn't just a massive inconvenience to you, it's against Code -- the NEC requires it so that the next electrician/homeowner who looks at the panel can actually figure out what breaker to shut off to make a circuit safe or get that sparking oven to quit.  In particular, it'd get dinged for busting 110.22(A):

110.22 Identification of Disconnecting Means.
(A) General. Each disconnecting means shall be legibly
marked to indicate its purpose unless located and arranged
so the purpose is evident. The marking shall be of sufficient
durability to withstand the environment involved.

and 408.4(A)

408.4 Field Identification Required.
(A) Circuit Directory or Circuit Identification. Every
circuit and circuit modification shall be legibly identified as
to its clear, evident, and specific purpose or use. The identification shall include an approved degree of detail that
allows each circuit to be distinguished from all others.
Spare positions that contain unused overcurrent devices or
switches shall be described accordingly. The identification
shall be included in a circuit directory that is located on the
face or inside of the panel door in the case of a panelboard
and at each switch or circuit breaker in a switchboard or
switchgear. No circuit shall be described in a manner that
depends on transient conditions of occupancy.

Second, what you have is indeed a Multi-Wire Branch Circuit (MWBC) -- the 52V on the black wire with breaker #23 OFF is stray capacitive coupling from the still-live red wire.  The red wire, of course, is still live because of another Code violation, this time of 210.4(B):

(B) Disconnecting Means. Each multiwire branch circuit
shall be provided with a means that will simultaneously
disconnect all ungrounded conductors at the point where
the branch circuit originates.

So, it's time to find the breaker that turns off that darn red wire (leave #23 off while you do this!).  Hopefully it will be adjacent to Breaker #23 -- in that case, you can get a handle-tie from the electrical supply house and handle-tie the two dodgy breakers together to fix the issue as per 240.15(B)(1).  If the builder was as clueless as I fear though, that breaker is somewhere totally else in the panel -- something you'll want an electrician to fix.


Remove tile, or not when changing from range vent to a microhood?

I would recommend leaving the tile in place (if it is aesthetically acceptable) in case you (or a future owner) ever want to change back to a traditional vent hood; the micros do not last forever either, a future change of style or brand will likely be a different size.


Removing Shower Tiles from Waterproof membrane

1) if you can yank the tiles without damaging the waterproofing layer below, you are fine.  You can do a water test leak once the broken tiles are removed.  Plug the drain, put a stack of coins on the floor, put water up to the coins level and check back in 24h.

2) you can regrout no problem. not sure what you call waterproof grout, but you can use any.  its purpose is not to hold water above the tiles.  The shower is designed to handle water that penetrate under the tiles and redirect it to the drain.

that said, what exactly is that black thing under your tiles?  Are you sure it is the waterproof membrane?  it might just be your deck mud.  In that case you could just patch it.

redoing a shower is a lot of work, thus make sure you have no other option first.


Bathroom in-wall exhaust fan with dimmer?

This kind of fans usually use a shaded-pole motor. From wikipedia:

  they are compatible with TRIAC-based variable-speed controls, which often are used with fans

So it appears the fan should be fine.

But there is some risk to the dimmer due to voltage spikes generated by the inductive load. You could try to find a dimmer switch that is rated to control inductive loads, or you could just try it out. A typical fan is pretty low powered device and a typical dimmer might be able to handle the small inductive spikes it will produce.


Assessing the cause of freezer coils icing up

Like the OP said. "It's a sealed system." If it was a leak it wouldn't "remove heat" at all. (fridges don't cool, they remove heat.) Automotive AC's DO leak, slowly, because they use rubber hoses/lines. So forget about the "low refrigerant", that ain't it.
The problem is one of three things. First (and most likely) the defrost timer. It's usually located in the plastic housing in roof of fridge compartment. Look for a larger hole that does not have a Phillips screw in it. Use a flathead screwdriver to turn the flat head looking plastic piece you'll see inside that hole. It's like a timer you use for your Christmas lights for example. Turn it until you hear a loud "click". Listen for your compressor/motor to turn off. If after about 5-10 minutes your coil starts dripping water/black heater coil bar gets hot (the header runs along coil; don't touch it, it gets real hot) then your timer's shot. Go online with your fridge model number and order that cheap part. Remove the screws that hold that plastic cover on, unplug the old put in the new, WITH THE FRIDGE UNPLUGGED. Turn the new timers screw until 2 clicks when u install it so it's in cooling mode.
If it does not heat up it's probably the defrost thermostat (a little disc mounted by coil.) Test with multimeter. It should have continuity when it is at freezing temperatures and should change to open circuit when the temperature rises above approximately 37 degrees F.
If that checks out then it's the heating coil rod. Double check the timer/thermostat before concluding it's that because it's a bit of a job to replace and least likely problem.
There is also a slight chance that it could be cause by a bad door gasket but you won't see major solid freeze up, just excess, making the unit work harder and run longer than it should. Here's a decent video on this issue. https://www.youtube.com/watch?v=2kNfNfHTgCo
He does keep calling the timer "the thermostat" but corrects himself in captions.


Raising fan speeds during heating season can be counter productive.  Shutting vents off does not mean more air will flow as we desire.  In most instance power consumption increases.  The best option is to increase duct size for a significate portion of the run if the duct was properly sized to begin with. Duct runs should never run over 25 feet remaining the same size.  Duct runs generally should be limited to no more than 20 linear feet. A 100 square foot room generally will need a 6" duct.


PVC drain pipe that the washer empties into is echoing all plumbing sounds

If you didn't, you should have installed a trap in that drain line to keep noise and smells from coming up the line. Make sure it is low enough to have a good amount of drain pipe above the trap so when the washer drains the water does not overflow from the pipe. If the drain will be inside the wall make sure you use a glued trap so no joint will come loose at a later time.


How to reduce brightness of LED spotlight permanently without dimmer?

They're called cinematic gels

They are just a gray filter that you put over the LED.  You can also get color-tinted, if you are trying to white-balance with other lights.

But a light one, and if you need more dimming, add layers.


The modern method tends to be a manlift, which are available for rental. I was raised on using staging, but both speed and worker safety (if you stay away from powerlines and otherwise operate according to instructions) are enhanced with a manlift, which is why you see a lot more of them and a lot less staging on most construction projects these days.


Bernzomatic propane torch won't light properly

HOW IT WORKS

Torches are simple devices.  The propane is stored as a liquid under pressure in the tank.  The valve on the torch provides an exit for the pressurized liquid propane.

When the valve is opened, the atmospheric pressure on the outside of the valve is less than the pressure required to keep the propane as a liquid.  The propane begins to change state from a liquid to a gas, pulling heat from the environment as it does so.  (This endothermic phase change is why the propane tank will frost up and feel cold when used for an extended period of time.  It is also why they often do not work in cold temperatures, as there is not enough ambient heat available for the phase change to take place.)

The pressure inside the tank forces the propane gas through the valve where it mixes with oxygen from the ambient air when it reaches the vent holes near the tip of the torch, and then exits the tip as a stoichiometric mixture ready to be ignited.

SOLUTION

There could be a blockage in the valve.  This could be caused by a piece of debris, or the valve could be frozen due to the endothermic reaction mentioned above. Clean or thaw the valve to fix.
The valve on the tank it self could be blocked/frozen, but this is unlikely as you tried an alternate tank. Let the tank slowly warm up to room temperature to fix.
The vent holes near the tip of the torch could be blocked, not allowing enough oxygen to mix with the propane.  Ensure these holes are free and clear to fix.
The ambient temperature may be too low for the endothermic phase change to take place.  This means that the propane exiting the valve is too dense to mix properly with the oxygen at the vent holes, so it won't burn when it reaches the tip.  Given the time of year and the problem you described, this is the most likely problem.  You will need to warm the tank back to room temperature in order for it to work.  CAUTION read the warning label on the tank before attempting to warm it. Do not place near open flame or excessive heat, as this could cause the tank to explode.


Need advice to prevent runoff water from going into neighbor's yard

..Your driveway would be the cracked concrete slab to the left, I assume?

If the picture is not misleading, there appears to be some slope towards the street. If so, rent a concrete saw or buy a concrete blade for a saw you own (but unless you own a water-cooled saw, a rental saw that is water-cooled will generally do a better job, faster) and cut a bunch of grooves 1/2" (or so) deep leading to the curb/gutter at streetside.

That may be all you need to do, or you may need to make some sort of raised edging at the right side of the driveway. That would probably best suit the area if formed from concrete, but something like a rubber glue-down garage door bottom seal (the type that's stuck to the floor, not the type that's stuck to the door) might be quicker and cheaper, until it dies in the sun and needs to be replaced.


How can I repair a float valve that is blocked open?

I bought a new valve and replaced it.
All works fine now.


Issue replacing a regular 3 way switch with smart one that requires neutral

Yes, that box is missing the neutral.

The National Electrical Code did not add that requirement until 2011.

Smart switches require a source of constant power to work. Therefore, they trickle a small amount of current on the neutral while they are working. They used to trickle this current on the equipment ground which was decided to be unsafe by the code making community. However, these older style switches that do not require a neutral are still available and can be installed in your situation.

Return the switch you have and look for a "no-neutral required" type of switch. Depending on how "smart" you want your switch to be, you can find occupancy / vacancy style switches that do not need a neutral and use the equipment ground instead. Similar to this one.

Harper is correct in his observation that thermostats use a low voltage system that is powered by the HVAC system through a transformer. You cannot get a neutral here.

Good luck and stay safe!


Mold in grout or just stained by mold...is retiling needed?

My guess is that the mould has grown into the grout; live or not, the bio-gunk they have produced has stained the grout.

A complete re-tiling should not be necessary; you should be able to simply remove the old stained grout between tiles and re-grout. You can remove and replace the stained/mouldy caulking as well. There are attachments for almost any rotary/oscillating/reciprocating tool to dig out grout, and there are also hand tools available for delicate areas. Simply work back down to either the depth of the tile or until the staining is gone, apply one last coat of bleach solution or Tilex, let try completely, and then sponge in a new layer of grout, making sure to get it into all the crevices as deeply as possible. To prevent mould growth in the future, you can apply a grout sealant; this will absorb into the grout and cure into a waterproof layer that will prevent the mould from "digging in" like it did.

If you are sure the mould is dead, there are also "grout restoration" kits that will cover the stain, and some of these products will seal the grout, preventing water permeation and thus avoiding mould in the first place. These are generally cheaper and easier than a re-grouting. But, if the mold's not completely dead, and the grout isn't completely dry, the mould can come back under a layer like this and remain visible, or even cause the repair to crack and flake off.


What type of window screen/frame is this?

As mentioned in the comments to the question, most window manufacturers have custom window screens that fit into specific window profiles (though, at times, you can come across very similar or identical profiles, depending on whether or not a manufacturer shares a supplier with a competitor).

For the screens that you have with damaged mesh, you can replace/repair those by procuring new mesh and new splines*. To remove the screens without cutting them out you typically just have to pry or pull out the splines from the narrow grooves in the screen bars (as those splines are what holds the mesh into place) which will allow you to remove the mesh in one piece. To install the new mesh, drape it over the screen frame, allowing for excess material to hang over the sides. With new splines, use a narrow/dull tool to press the spline+mesh into the groove in the screen bars, making sure the mesh is taught. Once in place, trim the excess spline and mesh material. There may be a warp in the screen framing from the way the tight mesh pulls at it but that is normal (that warp typically goes away once on the window).

In the case of the damaged spring locks that hold the screen into place (or missing screens in general), you will likely need to go to a window supplier/manufacturer to replace or repair the screen. However, if the window is too old or you are unsure of who made the window, you may need to find a substitute instead. Finding a substitute may require you to visit and consult with a couple sellers/manufacturers about using their products in place of your damaged screens. Though, keep in mind, replacements may not necessarily fit well but it will at least do the job.

You will likely be directed to the Service department for this and I would recommend taking with you at least one of your screens for reference along with clear pictures that show what the window profile looks like. Those pictures are needed to give a Service tech a better idea of where and how the screens are mounted. (Note: window manufacturers will require specific measurements before ordering replacement screens. Depending on the company, those measurements may be taken by you or a Service tech on site. I recommend waiting for feedback from a Service tech whether his screens will fit in your window first before taking measurements. He/she should tell you what part of the window to measure).

*Metallic wire or rubber lines that are typically pressed into narrow grooves in the screen bars. The splines are what hold the mesh into place.


If you have limited time onsite I would not spend a lot of time making 20 cuts, regardless of the method. Just cut them into 5 foot lengths or whatever you need to get them in your car and finish up at home. I think you will be pushing the battery life of even a high-end lithium set making so many cuts through large pipes.


The total weight of materials in a room is not really the question. The concern, if any is how many pounds per square foot. This will vary depending on what size joists are supporting the floor. Common residential construction is build to handle a dead load (materials/fixtures) of 40 to 60 psf averaged over the entire floor not counting load bearing wall materials. Live load is people.  Lets say you have a 10ft X 10ft room @40psf, the total load rating would be 4,000 pounds averaged. This link has some charts if you want to read more. http://www.assakkaf.com/Courses/ENCE355/Lectures/Part2/Chapter2a.pdf

In your case, there should be no structural changes or issues at all.


Looking to see if I'm wiring a multiwire branch circuit correctly

They aren't two separate circuits.  They are one multi-(hot)-wire branch circuit.
You will need to feed it from either 2 breakers handle-tied, or a 2-pole breaker.  This can be a GFCI breaker.  Unfortunately because it is 2-pole, using a GFCI breaker does not qualify you for 12” cover of burial depth so you must still be at the usual 18” for PVC conduit or 24” direct burial.
You could throw another gray wire into the pipe and make them 2 plain circuits, but that would mean 2 circuits to an outbuilding, and that is not allowed.
Unless the second circuit has a different voltage or form of control, for instance if it was switched from the house because you keep forgetting to turn off the shed lights.
A 3-way switch as a disconnect doesn't work, since there is no definitive "off" position which firemen can rely on to de-energize the structure, and further, 3-ways don't de-energize the structure at all. They simply exchange which of the 2 travelers is hot.
Other than that, your wiring is correct; you are using LINE and LOAD correctly.  The rule of thumb with GFCIs is that for any given cable, if any wire comes off the LOAD terminals, all wires must do so. Except for safety ground, obviously.
Your approach of splitting an MWBC into two simple sub-circuits is a common approach, and makes GFCI a lot easier to deal with.  When you make this split, after the split, GFCIs will work as in a simple circuit, and there is no further need to pigtail neutrals.   You must pigtail them in the switch box but not receptacle boxes.


Can I use a 50 amp range cord to connect a new dryer to a 50 amp receptacle?

The dryer could pull 50 amps if it malfunctions or sustains damage. Use a breaker that's appropriate for the equipment.

Why would you change the cord and not the receptacle? It probably violates code to use a cord with the 50-amp configuration on a 30 amp circuit. Someone down the road could plug a range back in and have an overload situation.

Change the breaker and the receptacle.


Is permeable concrete suitable for a houses foundations?

If you want to just let floodwater flow through, use a post-type foundation with either no walls or properly designed lightweight breakaway walls that will not impede water flow - plenty of examples of this in new construction in hurricane-prone areas. Park cars or other incidental storage under the house, let water flow right through when it comes in large quantities. Get it professionally designed so it actually works when the water comes.

I can't see that pervious concrete would have any benefit - if a mass of floodwater strikes it, it acts like a solid wall, with predictable (bad) results. For less massive water flows, it leaks. It's primarily of interest/use for reducing runoff from paved areas such as sidewalks or driveways (water can go through, rather than running off the edges in larger amounts.)


The flap may not be seated well at the bottom of the tank.  So the first, and cheapest step is to replace the flap.  However, if you've been adding tablets or chemicals to the tank, those can corrode the PVC fitting (flange) where the flap seals.  In that case you need to replace the PVC flange.

The smell is a second issue.  That has to do with sewer gas getting into the room.  The other answers suggest the wax ring.  That might be right.  Does the commode wiggle when you sit on it?  If it seems steady, it might come from a dry trap elsewhere in the room.  If you have a sink or tub that isn't used much, make sure you periodically pour water down them.  This puts a gas barrier in the trap, without which, gas comes into the room.


Both your friends are right.

Your electrician friend is right.  Wiring breakers are specifically sized for the load capability of the circuit.  If you put a 20A breaker on a 15A capable circuit, then congratulations, you've created a fire hazard!  (Circuit can now potentially overload carrying more amps than intended, overheat, and ignite.)

Your co-worker is right.  A breaker which trips repeatedly after replacing (wrong match or not) is not a problem with the breaker.  There is something wrong with the wiring or something connected to it.  Since you have nothing connected to it and it trips, that means your wiring has been damaged - possibly by a rodent of some kind.

Shut the breaker down for now and hire your first friend to troubleshoot it.  Electricity is not something to fiddle with if you don't know the rules well enough to avoid accidentally risking burning your garage down.  (Hope it isn't attached to the house!)


something similar to zip ties? (heavy duty)

250lb cable ties are made, yes. "industrial zip ties" seemed to be a pretty good search string for finding sources.

Probably more the cold making the plastic brittle than the basic strength of the zip tie. They do make "large, industrial" zip ties (I've seen 3 feet long and half an inch wide, and they probably go bigger) but you'll probably get better cost and service from rope, and learning to tie a "trucker's hitch."


Should I add a grease trap to a long drain run from the kitchen?

I would just use an enzyme once a week or once a month. Buying a case of that stuff will be less expensive than making enough space under your sink and installing a (stinky, smelly, disgusting) grease trap.

And the enzyme stuff is not made up of harsh chemicals.


How to move stacked washer/dryer from closet

Furniture movers are glides that slip under the feet of furniture or appliances to allow then to slide.

The hard plastic slides on rugs and the fuzzy covers slide on hard floors.

You can slip a pair of these under the front of your unit and, if you can, under the back legs as well. If not, tilt the unit slightly forward and pull. This is best done with two people.

These stackables are usually placed one at a time, but the upper unit clips into the lower fairly firmly. There is often a screw connection.  If there is not room to get behind to disconnect the upper, better to pull them out as a unit. Almost always the lines (water, power, gas, vent) are long enough to get the unit free of the closet and to then reach behind it, but check as you go, using a mirror if need be.


Low Faucet Flow Both Hot and Cold -- Aerator Clogged

You have sediment in your pipes.

Replacing the valve will not fix this.

Try thoroughly flushing your lines through faucets that don't have aerators. Such as, the outside hose valves and utility sinks. Remove the aerators from other valves and flush those lines too.

Then see if you get better flow.

Good luck!


Not likely will it be possible to replace the two 30A breakers with 40A breakers.

The wire size (AWG) for a 30A circuit should be 10 gauge. Proper wire size for a 40A circuit is 8 gauge if the run from the service entrance to the tankless heater is a reasonably short distance.

So do not simply replace the breakers like you asked. The breaker's primary function is to protect the wiring from over current so as to prevent a fire in overload or short circuit conditions.


What wood to use for external steps on a metal box-section frame?

I assume that the scaffold boards are SPF (spruce, pine, or fir). If so, they'll gray out and start to rot within a year, mostly at the contact points with the supports. If you were to seal them well before installation they'd do a bit better, but only by a few years.
Some wood naturally resists rot, such as cedar, redwood, and teak. They should still be sealed, though, to preserve appearance.
Otherwise, treated lumber is generally the most cost-effective. Since you don't need it rated for ground contact, almost any will do. It'll last 10-20 years, depending on various factors relating to moisture.


Well those stupid infomercials would say to "wrap it in flex tape," don't do that, or wrap it in rags. (Fiber fix would be better then both, but please fix it properly.)

That looks like a copper compression fitting. As such just tightening it probably will not stop the leak. There is a small chance that will work, it may have just worked its way loose over the years so start by simply tightening it, a little. Do not over tighten it. After a compression fitting is tight over tightening it will only make it worse.

Unfortunately if it still leaks it is a bit of work. Turn off the water, open up the fitting and replace the brass compression ring in side there. The trouble comes in getting the old ring off. You will either need a compression ring puller or a compression ring cutter (a rotary cutoff tool can be used, but be very careful not to damage the pipe).

With the new ring on, tighten the fitting down it is about one turn after it makes contact.


If you have any HVAC equipment mounted on the roof, you are going to be REQUIRED to have a GFCI protected receptacle next to it for service equipment. But barring that, I wouldn't do it: no need for it,  waste of money, possible site for future leaks and then it will get in the way of the future re-roofing project.


Adding a single light switch from a 3 way light

Short answer you can't.

If what you are describing is correct you only have three conductors in the box attached to the light fixture. That would be a ground, neutral and a switch leg from the 3-way switch. So you do not have a source wire in that box only a switch leg. Your best option to install a separate switched circuit for the second light fixture and run a completely new switch and switch leg.

Hope this helps and good luck.


How to switch an HDMI cable through and existing wall (hole)?

you can try to tape the new HDMI cable to the old one and fish it through the wall. Hopefully you wire isn't stapled to anything.


Identifying how this switch with indicator light is wired

Ok. So the indicator lamp is on when the light is on.   And if either your or the neighbor switch the light on, it's on.     This is unusual, but workable, and your description in your comment makes it all fit together.

The location of the pins on the switch/lamp is what gave me pause.

The switch and lamp are totally separate. They don't even have tabs to break off.

The cable coming from the other switch goes to your switch.   It carries hot and switched-hot.   It is wired in parallel with your neighbor's switch.  Your switch's two terminals go to the same place as your neighbor's switch's two terminals.    Eiher your switch or your neighbor's can give current a path to the light.

The cable coming from the light goes to your indicator lamp.  It is in parallel with the lamp, so the indicator gets power when the lamp gets power.  The two wires are switched-hot and neutral.

What struck me is it's a little bit wasteful.  The switched-hot is logically the same wire on both the switch and the lamp and could have been done with a single  /3 cable.

But this method is also alright, it's visibly obvious what is happening from how the cables are routed, so you don't have to logick it out.


Installing sliding door into a larger rough opening

Yes you can put a smaller door in, going smaller is easier because the header is already there, make sure when you frame your smaller door to leave a little room and make sure it is square x measure from corner to corner. I have helped a bunch of friends that made their opening exact and could not get the new window / door in because it was not exact or there opening was not square.
Extra wide trim on the outside can look like an expensive upgrade some don’t have a clue why we would do that.


Sizing grounding conductor for multiple circuits in conduit

Yes, and no.

The Equipment Ground Conductor for multiple circuits is sized for the largest circuit in the raceway. Sized from table 250.122 for the largest OCPD.

  250.122 (C) Multiple Circuits. Where a single equipment ground-ing conductor is run with multiple circuits in the same raceway, cable, or cable tray, it shall be sized for the largest overcurrent device protecting conductors in the raceway, cable, or cable tray. Equipment grounding conductors installed in cable trays shall meet the minimum requirements of 392.10(B)(1)©.

Additionally, the Code allows you to use the raceway, if it is metallic, as the EGC and save your money.

  250.118 Types of Equipment Grounding Conductors.
  The equipment grounding conductor run with or enclosing
  the circuit conductors shall be one or more or a combina- tion of the following:

  (1) A copper, aluminum, or copper-clad aluminum conductor. This conductor shall be solid or stranded; insulated, covered, or bare; and in the form of a wire or a busbar of any shape.

  (2) Rigid metal conduit.

  (3) Intermediate metal conduit.

  (4) Electrical metallic tubing.

  etc.

Lastly, if you have UF cable you don't need a raceway unless it is exposed to damage and it should already have an equipment ground wire in the cable.

Good luck with your project!


Does a software-controlled central heating programmer and thermostat exist?

They make Internet Controlled Thermostats already.  I would start with one of those, and then just build an interface for your phone that will interact with the device through the web.


Do you strip the outer sheath on romex when it enters a load center / breaker box?

Typically it is stripped back to where it enters the enclosure. There is a code minimum, 1/4", but no maximum. It could be argued that leaving most of the sheathing on is poor workmanship.

Sometimes I leave an inch or two to write the circuit ID on the sheath.

  NEC 2011

  312.5 Cabinets, Cutout Boxes, and Meter Socket Enclosures Conductors entering enclosures within the scope of this article shall be
  protected from abrasion and shall comply with 312.5(A) through (C).

  C) Cables. Where cable is used, each cable shall be secured to the
  cabinet, cutout box, or meter socket enclosure.

  Exception: Cables with entirely nonmetallic sheaths shall be permitted
  to enter the top of a surface-mounted enclosure through one or more
  nonflexible raceways not less than 450 mm (18 in.) and not more than
  3.0 m (10 ft) in length, provided all of the following conditions are met:

  a) Each cable is fastened within 300 mm (12 in.), measured along the sheath, of the outer end of the raceway.

  b) The raceway extends directly above the enclosure and does not penetrate a structural ceiling.

  c) A fitting is provided on each end of the raceway to protect the cable(s) from abrasion and the fittings remain accessible after
  installation.

  d) The raceway is sealed or plugged at the outer end using approved means so as to prevent access to the enclosure through the raceway.

  e) The cable sheath is continuous through the raceway and extends into the enclosure beyond the fitting not less than 6 mm (¼ in.).

  f) The raceway is fastened at its outer end and at other points in accordance with the applicable article.

  g) Where installed as conduit or tubing, the allowable cable fill does not exceed that permitted for complete conduit or tubing systems
  by Table 1 of Chapter 9 of this Code and all applicable notes thereto.


This is fine
Not stapling fished NM cables in remodel work is permitted by NEC 334.30(B) point 1:

(B) Unsupported Cables. Nonmetallic-sheathed cable shall be
permitted to be unsupported where the cable:
(1) Is fished between access points through concealed spaces
in finished buildings or structures and supporting is
impracticable.

So, fish away, and don't worry about tearing up drywall to get staples in.


The plumber came out today and showed me how to remove it. The Evil Greebo was right, the stem itself unscrewed. The plumber took off the handle and escutcheon, then put the handle knob back on to further unscrew the stem. He did this very slowly and used a lot of force. He had a lot of difficulty with the cold, and that is the one I had started with, so it is not surprising I was doubtful of this being the way it was supposed to work.

The plumber thinks it is Sterling, because those were popular around here years ago and they were low cost, the type that someone would put in the downstairs shower.


Wiring for new 40 amp wall oven and cooktop

My first concern looking at the subpanel is if that bare #6AL is in fact a ground and the two appliances are straight 240V then the two white wires connect to the buss should have some green tape on them. If it's not a ground but actually a neutral, where are the grounds?  You will need to ground everything.

I would try utilizing the #6AL XHHW since changing it out would be difficult. It is rated for 50amps according to my chart so the breaker in the main panel should be changed to a 50AMP. Since the two NM-B cables can easily replaced, change them to NM-B 3#8 and replace both breakers in the subpanel to 40 AMP.

Where actually is the subpanel?

News flash: The name plate on the oven states "four wire".  Major game changer. The new wire you run will have to have a ground. This will probably require you to change the #6AL run to 3#6cu plus ground or just run two 3#8 with gnd, one for each appliance, add additional breaker in main panel. Both breakers would be 40AMP and eliminate the subpanel.

If your owner's manual states that you can hook up the four wire appliance to a three wire source, then it is ok to do it.


Furnace: pipe is leaking when switched to air-conditioning

That plug is where I add biocides to prevent mold buildup in the pan, mold is the main cause of obstructions , if the pan is starting to drip you probably have some cleaning to do as the water should not build up in the pan and a small layer has probably raised the water level because it is acting like a dam.

I have had customers ask how can mold grow in there it’s only water and metal, well this is almost true but dust and fine organics get trapped in the coils and drip down to the pan, when the conditions are right a mold colony starts growing,
For this reason pros recommend having your unit serviced, adding this biocide treatment is a requirement for large commercial systems to prevent legionnaires disease, I have not heard of it in home systems but it is possible.
So you may need to clean and treat your pan or eventually the drain line will be totally blocked and the water may come out in other areas less noticed and cause problems.


Replacing standard light switch with dimmer

L2 isn't L2 any longer

L2 was clearly one of the outputs on your old dimmer -- it isn't on your new dimmer.  The output on your new dimmer is marked by the sine-wave-with-an-arrow-through-it (aka variable sine wave) symbol -- so put the wire from L2 into that port, and things should work.


Sizing I-beams for two Floors to replace LVLs

Notes:

I am not a licensed architect or engineer.   I do however produce plans that I get a stamp on or have the local inspector agree to.
I usually would not give someone advice on load beams that are not uniform - you are spanning two different load configurations here and doing a bit of stacking.
Since you already have LVLs and the description of your issue I am assuming that the load calculations are right, footers are suitable and working, and the support beams are sufficient.

I use https://www.engineeringtoolbox.com/ for a lot of information - I actually found the site from an architect that I use.   The chart below is from their site.   I ALWAYS add an extra 25% of allowance to anything I size myself.  You should be using this as a reference and work with someone that can look at the full layout of your building.


What is this stake in my yard and can I remove it?

Looks like a run-of-the-mill landscape stake to me. They're used for securing plastic edging, fabric, etc. Could also be a tent peg. It's a horse apiece.

I'd give it a few taps with a hammer to loosen it, then try prying it out with a spade or the hammer with a block under it.


How should I caulk aluminum capping where it meets brick?

Backer rod and sealant is appropriate for joints between dissimilar materials such as that pictured in the question. Preparing the brick surface, correctly sizing the backer rod, and properly installing the sealant may all play a role in long term performance of the system.

Select the sealant for your application based on manufacturer's literature. The label on the tube often contains clear guidance.

Filling voids behind the joint with fiberglass insulation or with spray foam insulation prior to sealing may also improve thermal performance and reduce air infiltration.


What could be causing a moth ball like smell?

Given that those are very distinctive smells, the items mentioned are probably in the heating unit. Possibly as part of some animals's nest, if you don't have small children who might have put them there...might want to open it up and clear them out before you have a fire.


Conventional switches

When you have two switches controlling one circuit, they are both 3-way switches They are called that because they have three active contacts, one common and two travelers. They also have a ground and may have a neutral for extra features.

When you add any more switches beyond two, they each must be 4-way switches. These have two hot contacts in and two out and sit between the two three way switches (electrically in between, regardless of where they are physically). These also should have a ground contact and may have a neutral.

When you add a dimmer, it must replace one of the 3-ways, not the 4-ways. You also need a dimmer that is 3-way compatible (not all are).   Also, if you are using CFL or LED lights, make sure the dimmer is compatible (it should say so on the box).

Only one dimmer can be used. The other switches just turn the circuit on and off, at the level the dimmer has set.

Multiple dimmer systems

As @DMoore has said, there are newer electronic switch systems that allow dimming from multiple locations (as well as on and off). One switch is a master and the others are slaves. In effect, the master controls the circuit and the slaves send a signal to the master to do that remotely.

This system will give you more flexibility than a conventional switch system, but it is significantly more expensive. If you do not  need this flexibility, adding one 3-way dimmer is cheaper and easier.


Your ceiling drywall is probably not directly attached to any structural members.  It is pretty common in newer multistory buildings to put sound damping resilient channel between the two.  And there is only enough structural support for the drywall/lights and not any additional loads.


THHN through EMT - then convert to Romex?

You can transition wiring methods at a junction box.  Use the EMT wiring method up to the junction box (whole nine yards with fittings and clamps).  Then use the NM wiring method beyond it.  The junction box must remain accessible without screws, nails or demolition (other than the ones on the junction box lid, of course).  If you don't like the aesthetics of a blank junction box cover, then stick a receptacle there lol, or better, extend the conduit a little bit to a place you want a receptacle, and use an extra-large box so you have room for the splices. Then put a receptacle there fed off one of the circuits.

You simply splice wire to wire, except for grounds. Normally there isn't a ground in the EMT conduit, the conduit is the ground.  Any junction box will have a #10-32 tapped hole and you fit a cute little green ground screw there with a pigtail.  You tie the pigtail to the Romex grounds.

I get where you're a Romex guy and EMT/THHN feels alien to you.  I strongly recommend you "get acquainted with" this new wiring method.  It is actually rather versatile.  For instance, a conduit can take up to 4 circuits - or 8 with multi-wire branch circuits!  All circuits can share 1 ground wire, and if the route is entirely metal conduit and metal boxes, the conduit is the ground!  It's a fantastic system.

That the attic will be finished is precisely why to think about extending conduit.  Conduit lets you alter the wiring later depending on your usage.  Find it's too hot and want a window air conditioner, but a 120V one would overload the circuit with your PC/laser, and you'd prefer a 240V unit anyway?  Easy peasy - pop a few box covers off, pull two more wires, instant dedicated circuit.  With stranded wire, pulling is easy. I do it all the time.


How To Remove Decorative Logs From Stucco Exterior

I have removed similar but square beams using a hatchet and a hammer, with quite a few the split right at the anchor and I was able to remove the anchor with vice grips. There were a few that I had to split several times both horizontally and verticly until I found the anchor. The beams were embedded. Over the tar paper but the metal mesh had been cut I am guessing so they would be tight. We did restucco prior to painting and it looked fine but your slate shake/ cement board will look very nice and you wouldn't need to fill the holes.


Is it allowed to connect 14 awg ground wire to 12 awg ground

Assuming US here.

As long as there are both 12 gauge and 14 gauge grounds going back to the (same) electrical panel, that will be fine.  The reason for this, is that if something shorts out, it will take the "path of least resistance" to ground.  If there is at LEAST a 12 gauge and a 14 gauge path to ground, the 20 A and 15 A circuit will each have "big enough" paths to ground. (actually, now the path to ground is even bigger, assuming that the two circuits don't short at the same time).


This site has useful diagrams for wiring 3ways http://www.homeimprovementweb.com/information/how-to/three-way-switch.htm