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4 Answers

Insulating 1890's 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.

The basement is used for storage and mechanical so we cannot put down insulation on the ground. The other big obstacle is that there is a stream that runs under the house year round (20-40 gallons of water pumped via sump every day). The basement is always cooler than the house and almost always wetter for obvious reasons. I have two major concerns with doing this insulation.

Asked By joseph rosen | Dec 16 17
6 Answers

Which way should foil face on polyiso rigid foam face?

Correct me if I'm wrong, but shouldn't the foil face 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
5 Answers

REMOTE retrofit

I recently learned about the REMOTE/PERSIST building methods and think it'll work well on my house. I'll be removing old fiber cement siding and adding vapor barrier faced, shiplap, 4 inch polyiso (good deal on seconds from a local manufacturer). It's a small house, with only about 750 sq ft of wall space to retrofit (a newly built addition on one side). I've landed on exterior foam because I plan to replace the siding to match the addition anyway and don't want to settle for 3.5" of dense packed cellulose. The main floor is heated by a single ductless heat pump.

Asked By Pat Beurskens | Dec 14 17
12 Answers

Workshop with dwelling above: Heating advice?


Asked By User-6964558 | Dec 12 17
0 Answers

Are there any examples of Joe Lstiburek's Ideal Double-Stud Wall in the wild?

This is the wall I'm talking about: https://buildingscience.com/documents/enclosures-that-work/high-r-value-...

It's a double stud wall with the interior studs bearing, and sheathing applied to the exterior of the interior studs to form the air barrier layer in the middle of the insulation.

When I've seen this wall get brought up in the past, worries about constructability issues are often raised for two-story (or higher) buildings.

Asked By Brendan Albano | Dec 16 17
14 Answers

Repair or replace sheathing behind brick veneer?

I wanted to get some advice on what to do with existing sheathing material that is currently installed behind brick veneer in a 1980's home I'm currently renovating. It's located in Houston, is 2x4 wood frame construction on concrete slab foundation, and the other parts of the house have T1-11 and vinyl siding (which will all be eventually replaced), but my questions concern what to do behind the brick for now. Much of the interior has been gutted down to the studs due to issues with mold and pests.

Asked By sdcnyhou | Dec 8 17
3 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
30 Answers

Radiant floor heating using heat pump?

We live in a Zone 7 area and are building a one story 2000 sq ft on a slab and have decided we would like to heat the house with in-floor radiant. We have been told by HVAC specialists that the best solution would be geothermal, followed by hot water heat pump, electric hot water, then forced air heat pump and electric radiant. We don't have natural gas so that is not an option. Geothermal is out as it is nearly three times the price of the other solutions and this is a retirement home.

Asked By John Ball | Jun 19 15
7 Answers

Slab edge insulation and termites in Climate Zone 3A

My basement walls should be poured by the end of the month and I am wanting to get the details right in CZ 3A.

While slab insulation is not "required" for my climate zone, I am considering it for comfort reasons and to insure against the future (better safe than sorry). However, termites are common in my area and the house is on a wooded lot that will have plenty of food for them, so I am concerned about them coming up the edge insulation into the stud wall noted on the attached diagram.

Asked By Norman Bunn | Dec 15 17
4 Answers

True felt tar paper / grade D paper

As Martin has written many times, "felt paper" used to be made from rag, but is now made from paper. Thus when it gets wet it gets super weak.

Asked By Bryce Nesbitt | Dec 15 17
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