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19 Answers

Spray foaming the attic with a twist

I will be having my attic sealed and insulated with closed-cell spray foam. However, the design of my house makes this a bit more complicated because my roof cuts into the second-story ceilings at the front and rear edges of the house (will make more sense if you look at the attached pic).

Above this part of the ceiling, there is only some very old batt insulation (less than R-8) and the roof deck. The house doesn't have eaves/soffits, so there is no venting in this area.

In Energy efficiency and durability | Asked By Matt Culik | Aug 14 14
25 Answers

Subsurface rigid insulation and boring critters

I was speaking with my passive house consultant the other week, and she expressed concerns about boring critters and subsurface rigid insulation. She had such an experience with some insulation in her garden (It was put in one season and removed at a later time as she got back to completing the project.)
Now, I know all about the ate/termite protection used in these insulation products, but what about larger critters that would love to have a warm dry home?

In General questions | Asked By Steve Young | Aug 16 14
3 Answers

Rigid insulation between interior bearing wall footings and slab?

We're building a new 2-story home in central Iowa. It will have a below grade basement with 9' foundation walls. The slab will be about 8 feet below grade.

In Green building techniques | Asked By Silas Hoeppner | Sep 1 14
4 Answers

Unvented vs. vented roof

Hello,
I live in the Pacific north west, and will be building a home off the cost of Vancouver island this fall. The house is small, 700 square feet, with a 1 n 12 pitched roof as the design. We have not started construction on the house as yet and we want to deal with the roof in a way that will, of course, provide the best of all worlds.

In General questions | Asked By Jeannette Sirois | Sep 1 14
11 Answers

I'm currently struggling to explain why I want SIPs for my roof instead of trusses

My designer and I are designing a house as close to passivhaus standards as we can get. We have agreed to design it with SIPs but he thinks a truss roof with spray insulation would work just as well. I'm thinking a SIP roof eliminates potential for thermal bridging and is less costly to install versus the truss roof.

In Green building techniques | Asked By scott schroeder | Aug 29 14
5 Answers

Blower door tests and fireplaces

Most of the blower door tests that are mentioned on GBA give numbers under 3 or 2 or 1 ACH50. I'm guessing that none of these homes have a traditional fireplace. How much does a traditional fireplace with standard chimney damper contribute to air exchange numbers? What are some recommendations for improving a house with fireplace and chimney?

In Energy efficiency and durability | Asked By Derek Roff | Sep 1 14
5 Answers

Stepped Foundation Metal Flashing Detail with Exterior Rigid Foam

I am replacing my existing siding and I am doing the following -stud - 5/8" plywood - 1-1/2" of Polyisol, 3/8", WRB, rain screen, fiber cement siding. The house is in the San Francisco bay area on a hill with a stepped foundation.

In Energy efficiency and durability | Asked By Randy Mason | Aug 30 14
4 Answers

My family room has a painted T&G wood-planked vaulted ceiling that leaks air

I have a question about an effective way to solve an issue in a house with a large family room that has a painted T&G wood planked vaulted ceiling that leaks air and makes the house very cold in the winter.

In Green building techniques | Asked By Bruce Howe | Sep 1 14
1 Answer

Vapor barrier in bathroom remodel

Hi,

I am in the middle of a bathroom remodel. My house was built in the late 60s and is located in climate zone 6 (Quebec). My question is about the damaged kraft paper that is supposed to act as a vapor barrier. From what I can see the wall assembly is (from the interior):

- Drywall
- Kraft paper
- Furring strips
- Some cardboard fiber and studs
- Probably batts insulation (I can't see behind the cardboard)
- Tar paper and exterior sheeting (brick)

In General questions | Asked By Guillaume Dumont | Sep 1 14
1 Answer

Can TrueFoam Foundation Plus Type 2 rigid foam be used as a vapor barrier?

I am finishing the exterior basement walls in my new home. My plan is adhere rigid to the foundation walls, after that I'll be putting down dricore subfloor, then studding up 2X4 walls on top of the dricore. There will be an air gap between the rigid and the 2X4's as I am laying in R-20 "2X6" batts. Plastic vapor barrier will complete the system before the drywall.

In Green building techniques | Asked By Mark McKenzie | Sep 1 14
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