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5 votes

Cost effective insulation for a 100 year old home?

I'd go with rock wool batt insulation in the stud bays. Rock wool has several advantages over fiberglass. Better sound deadening ability. Better fire resistance. R-value unaffected by moisture. ...
Fresh Codemonger's user avatar
5 votes

Can tile, cement, and grout rubble be used as fill under crawl space vapor barrier?

All those things combined don't amount to much volume. If your goal is to install an inorganic layer for sanitation reasons, this doesn't do much for you. You'd need to be sure that no sharp edges ...
isherwood's user avatar
  • 141k
5 votes

Vapor barrier (sheet) over concrete pad below ground level deck?

I would not. Your lumber is treated against rot anyway, and poly will mostly serve to trap moisture and encourage mold and odor. Let it breathe.
isherwood's user avatar
  • 141k
4 votes

How to deal with upside-down insulation?

Nearly all of Virginia is considered to be in the "mixed-humid" zone. On an annual average, moisture migration is fairly evenly distributed (alternating toward the interior and toward the exterior). ...
James Olson's user avatar
  • 1,366
4 votes

Can the vapor barrier between a dry floating concrete slab and linoleum flooring be foregone?

Insulated slabs usually have vapor barrier underneath. Since you did a test and found no moisture, there should be no problem installing vinyl flooring on it.
isherwood's user avatar
  • 141k
4 votes
Accepted

Fixing a drywall hole near shower

Looks like an old-school shower area install with roofing felt (not plastic, at least looking at the pictures.) "Rubbery and a little paper-like" - felt soaked in tar. Probably still smells ...
Ecnerwal's user avatar
  • 220k
3 votes
Accepted

A creative Eco-friendly Underlayment for a metal roof?

Red Rosin Paper (which is a bit old-school, but can still be found) would fill the bill, I believe. It's plant based. Seems to be getting sold for floors now, but was the thing people used before ...
Ecnerwal's user avatar
  • 220k
3 votes

Can I use a ground trench as a concrete foundation form?

You can purchase "insulating concrete forms" made of foam that are designed and reinforced to withstand concrete pressure (if not damaged while being installed - there are some horror ...
Ecnerwal's user avatar
  • 220k
3 votes

How do I install a vapor barrier on the exterior of an existing wall?

Vapor barriers belong on the warm side of the house. The answer stating that vapor barriers belong on the outside only because air conditioners is assuming that everyone lives in a warm climate and ...
ickybus's user avatar
  • 853
3 votes

Would unfaced insulation with a plastic vapor barrier work better than faced insulation in a finished attic?

Poly sheeting provides an unbroken vapor barrier which can be sealed to adjacent sheets, framing, etc. using proper caulk sealant. Faced insulation leaves less effective joints between every cavity. ...
isherwood's user avatar
  • 141k
3 votes
Accepted

How do I vapor seal around a fireplace exhaust?

If (as I'd expect) the concentric stovepipe is rated "zero clearance to combustibles" you can seal right to it. The exhaust is in the inner pipe, and the outer pipe is cooled by the air ...
Ecnerwal's user avatar
  • 220k
2 votes

What are the pros and cons of adding a vapor barrier behind shower backer board?

Follow manufacturer's instructions first and foremost. Also in places with hot humid climate vapor barrier on the inside wall causes more trouble than it fixes. https://www.jameshardiepros.com/...
Michael Gleason Jessamine's user avatar
2 votes

Vapor Barrier for Wine Cellar

Closed-cell foam insulation is a vapor barrier itself. If this closed-cell foam is continuous, then you shouldn't have any issues. If it is just in the cavities between wood studs, then the studs may ...
littleturtle's user avatar
  • 1,072
2 votes

How to deal with upside-down insulation?

Kraft paper is a vapor barrier (or more accurately a retarder), and in my opinion it's no more a fire hazard than the lumber it's stapled to and all the stuff you have in your home. Inspectors ...
isherwood's user avatar
  • 141k
2 votes

Insulating existing basement wall

Much depends on the dryness of your basement. For most basements, worthy of being made into finished living space, 3 mil. plastic sheeting between the framing and basement wall should be sufficient ...
James Olson's user avatar
  • 1,366
2 votes

Proper way to install subfloor in kitchen

We use to specify building paper between the underlayment and subfloor. About 10-15 years ago we stopped. Now, we worry about moisture (vapor) getting trapped between the underlayment and subfloor. ...
Lee Sam's user avatar
  • 23.3k
2 votes
Accepted

How good of a vapor barrier is OSB in a dirt crawlspace?

Moisture barriers are not a water tight seal kind of thing. If you cover 75% of the dirt then you should reduce the mustiness by about that much. Anything will probably be an improvement and if is ...
ArchonOSX's user avatar
  • 20.1k
2 votes

How should I mend the plastic sheeting behind my drywall?

The standard now is to never do that again especially if you use air conditioning. Building science has determined this was a very bad idea because it traps moisture within the wall cavity. Here's a ...
Been There's user avatar
2 votes
Accepted

Is it necessary to replace plastic covering pink insulation in bedroom exterior wall?

You are fine. Vapor barrier holes of that size and bigger are typical in wall construction, in the form of switches, outlets, plumbing, etc. Let's keep calling it a vapor barrier. Makes geeky ...
NPM's user avatar
  • 2,021
2 votes

Removal of Plastic Vapor Barrier

And this is why you don't put vapor barriers on both sides of a wall Your problem is that you have a vapor barrier on the inside (the plastic right under the drywall) and a vapor barrier on the ...
ThreePhaseEel's user avatar
2 votes

Should I use a vapor retarder in Missouri?

The US Dept of Energy also says 1/16" back drainage cavity for siding is appropriate even though capillary action occurs up to 1/4". Point being, the department of energy tends to lag significantly ...
Joel's user avatar
  • 31
2 votes
Accepted

How should I repair small tears in the kraft paper insulation caused while running a new water line?

You're right that your bathroom will have a lot of moisture in it, but if that much gets through to your insulation you're not ventilating enough. Make sure you run your bath fan regularly and for ...
isherwood's user avatar
  • 141k
2 votes
Accepted

Vapor barrier behind electrical panel?

Since the garage is not within the conditioned envelope, then no The key to understanding a "vapor barrier" (really, an air barrier) is to understand that it is part of the system that separates "...
ThreePhaseEel's user avatar
2 votes

Densheild tile backer board use advise needed

I use Denshield on every shower i do. I understand the manufacturers recommendations but i think it is good practice to go the extra mile and use a waterproofing membrane on all seams and screw ...
Alaska Man's user avatar
  • 13.6k
2 votes
Accepted

How to insulate metal roof on shed and avoid condensation?

You need to prevent air from getting to the metal. If no air circulation there is no moisture will condense on the inside. Spray on insulation works well but is fairly expensive, Fiberglas works but ...
Ed Beal's user avatar
  • 103k
2 votes

Should I put a moisture barrier between a single ply of pressure treated (PT) plywood and a second non-PT ply when constructing a shed?

Dont put moisture barrier between, it will just trap moisture and rot quicker. Moisture for shed should be under structure. But if it collects rain water on top you are just making humidity worse. Pt ...
justin j's user avatar
  • 391
2 votes

Cost effective insulation for a 100 year old home?

Vapor barrier goes on the WARM side of the insulation. So plastic up against the boards and insulation on top is a bad idea. If you've got the walls down to studs and sheathing, furring out the studs ...
Ecnerwal's user avatar
  • 220k
2 votes
Accepted

Do I need a vapor control membrane inside the roof if I have a breathable underlay outside?

Vapor barrier against the inside of the building envelope is to prevent interior moisture, caused by normal human activity, from condensing at the dew point. That usually occurs somewhere in the ...
isherwood's user avatar
  • 141k
2 votes

OK to forego vapor barrier under concrete slab if pressure-treated sill plate is used along with sill gasket?

Our garden shed and greenhouse are built with pressure treated plates over gasket on concrete slab without vapour barrier. The soil underneath was compacted well in order to avoid contamination during ...
P2000's user avatar
  • 16k
2 votes
Accepted

Identifying thin plastic sheets between interior walls

That plastic is indeed not a vapour barrier (retarder). It is more likely packaging or wrapping for the insulation inserted in the wall, like "Poly-Wrapped Fiberglass Batt Insulation" The ...
P2000's user avatar
  • 16k

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