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36 Answers

1952 Cape Cod


First-time poster. In the past 2 months, I’ve read a hundred or so GBA articles and comment threads; I’ve been amazed by the expertise and generosity of the community. I’ve also read extensively at buildingscience and finehomebuilding -- I’m new to but very interested in building science. Here’s why:


Asked By Emerson W | Dec 11 17
5 Answers

Cold bedroom fix?

Climate zone 6A, my daughter-in-law's 1990s half of a duplex. Cold bedroom juts into garage (see photos). Fiberglass (6"?) that's below bedroom subfloor isn't in contact with it - about a 2" gap as far as I can tell.

To take the photo that looks up at the subfloor, I reached my camera through the gap below the wall sheathing, while simultaneously pulling the fiberglass aside. So, basically no access to push the fiberglass up against the subfloor.

Asked By Jonathan Beers | Dec 15 17
1 Answer

How do I insulate brick wall from the heated side of house?

I am working on a 1978 built, brick house in Juneau, Alaska. Was seeing moisture on drywall and some mold. After removing drywall found 2X2 nailers, 2 feet on center nailed at the grout line. Between the nailers was 1.5 inches of white bead board. Found a few places where the air was leaking in and believe that they have been taken care of.

Other info:
wall is above grade
appears to be single, standard size, red brick constructed wall

I am not sure how to continue...how much insulation can I add for the climate and not damage the brick?

Asked By Daniel Hall | Dec 17 17
0 Answers

Garage Doors: Any improvements on low infiltration, high R value?

I've read a few GBA discussions about the sorry state of garage door R value and infiltration. The conclusion was to look first for infiltration values, and then question the r-value because it probably does not apply to the entire door assembly.

I'm wondering if anyone has any updated information on any products that might be better that others, and hopefully something affordable.

Asked By c l | Dec 17 17
0 Answers

Rim Joist insulation with blocking

I am finishing my new construction basement addition and I'm a little unsure of what to do with the rim joists. The rim joists are 2x12 LVL with double rims over two groups of two windows. A cripple wall separates the rim bays from the foundation. Tyvek covers the sheathing with a rainscreen gap. There is TJI (I beam) blocking in between each floor joist, leaving an open space behind each block. I currently have R30 Roxul filling the rim joist bays but I'm wondering if I should pull it out, install rigid foam-sealing the edges with spray foam, then reinstall the Roxul.

Asked By pat beurskens | Dec 17 17
4 Answers

I seem to have condensation buildup on the inside of a dual-walled horizontal flue pipe coming from heater

There is a hole on vertical portion of same flue pipe, although single wall at this point. Would this hole cause moisture buildup on inside of duct and the water would accumulate in low portion of the duct and leak out?

Asked By Graef | Dec 16 17
8 Answers

Insulating a 1890s floor from unfinished basement

I am looking to insulate the floor in an 1890s victorian house in Maryland (zone 4) that has an unfinished basement. The floor of the first floor can be quite chilly and its a definite heat loss.

Asked By Joseph Rosen | Dec 16 17
13 Answers

Workshop with dwelling above: Heating advice?


Asked By User-6964558 | Dec 12 17
2 Answers

Garage Wall Insulation


Asked By Mike McLaine | Dec 14 17
10 Answers

Which way should the foil facing on polyiso rigid foam face?

Correct me if I'm wrong, but shouldn't the foil facing on polyiso face the interior in climate zone 5 to help retain heat? It will be used on basement rim joists. The heating season is obviously longer than the cooling season.

Furthermore, should I leave an air gap between the foam and the wood or should I place the foam directly against the wood before spray foaming the perimeter?

Lastly, should I seal the perimeter of the rim joists with the one part foam prior to installing the rigid foam and spraying around the perimeter of that?

Asked By BuildingNewb | Dec 16 17
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