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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
20 Answers

XPS versus EPS Underslab Foam

Hi. I am back and forth on whether I should use XPS (blue board) or EPS for the insulation underneath my slab. I understand the qualities of each regarding water absorption and drying out, but would it (XPS particularly) affect the long term performance to the point where the slab is compromised? I also understand the pollution associated with XPS manufacturing. I have the option of purchasing 6" (house in very cold climate) of EPS (R-24) or 4" of XPS (R-20). The EPS is less expensive per inch, however, I need to pay for shipping which jacks up the price.

In Energy efficiency and durability | Asked By Matthew Michaud | May 2 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
10 Answers

XPS vs. polyisocyanurate

Hi,
I am currently redoing the exterior of my house with a new vinyl siding and changing all windows. My house was built in the mid 80's and have 2x6 studs with Batt Insulation and mostly without a vapor barrier... but the insulation is not great, especially the air goes through the house.
My question is what is the best insulation for me to put outside the house underneath the vinyl siding. My windows will allow me to go up to 1 inches of exterior insulation.
So XPS with Typar? Polyisocyanurate (IKO Ener Air )? Others?

In Energy efficiency and durability | Asked By Jason Haché | Aug 29 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
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