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2 Answers

Rockwool (Roxul) sheet sizes. [2' x 4' or 4' x 8']

We're about to start insulating the foundation walls with Rockwool/Roxul Comfortboard IS 80.

In all of my reading I have seen theses boards come as 2' x 4' boards. Even then I have read of some difficulty handling.

Our supplier is suggesting 4' x 8' boards of the same product, but I am worried that this will be even more difficult to work with.

Has anyone here worked with Comfortboard for vertical exterior insulation and have experience witht he 2' x 4' or 4' x 8' board sizes? Any thoughts on the matter?

Asked By Ethan T ; Climate Zone 5A ; ~6000HDD | Mar 22 18
10 Answers

Zip or Zip R?

I've been doing a lot of research trying to find the best option for residing by 1920 house located in Climate Zone 4 - mixed-humid. Existing plaster and lathe walls on the interior. I've asked a few questions on this website and the responses have been very helpful so I'm asking one more.

I'm planning to remove the existing vinyl siding and wood clapboards and spray foam the walls from the exterior with medium density spray foam to give the stud cavity an R value of about 21.5.

Asked By Michael Mohr | Jan 24 18
28 Answers

Taping of Roof Sheathing / Wall to Ceiling Vapor Barriers

We building in climate zone 6A. We have planned unvented cathedral ceilings and we are planning to do 4" (or maybe just 2" depending on cost) of closed cell spray foam applied to the underside of the roof deck. We are then going to net and blow in fiberglass to the remainder of the cavities between the 16" TGI's.

I'm planning on the closed cell foam being my air and vapor barrier on the roof. On the walls the my air barrier will be the taped sheathing and the wall vapor retarder will be latex paint.

Two questions:

Asked By Steve Mackay | Mar 21 18
7 Answers

Wrapping subslab poly over perimeter foam

I am trying to figure out how to connect my subslab poly to Intello air Barrier. As you can see on the attached detail, I am proposing taping the poly to the foam... and the Intello is taped to the sill plate and perhaps the top of the foam. I'm not sure how best to bridge this gap. I know that the foam isn't an air barrier, but I'm not sure how to bridge this gap... perhaps I could use some sort of faced foam at this location?

Asked By Ethan T ; Climate Zone 5A ; ~6000HDD | Mar 21 18
3 Answers

Ideal window depth to minimize window perimeter thermal bridging through frame

I am replacing the windows and redoing building envelope in my 30 year old house. Currently have 2x6 framed wall, covered with 5/8 tentest type fibreboard and then wood siding. Windows are original 30 year old solid wood. I am replacing windows with the following: Basic flush mount vinyl high efficiency windows, 4 5/8 thick with interior jamb slot for interior trim to be added to.

Asked By Clark | Mar 21 18
28 Answers

Insulate this!

This one-room addition has no foundation. There is insulated in walls (likely R11) and ceiling (likely R19 - certainly no more), but not in the floor. As you can see, outdoor air can simply pass through the open space under the floor. When the flat EPDM roof needs to be replaced in 5-10 years, we will install exterior foam board outside the roof deck. Heating is primarily warmed air from rest of house or propane fireplace. Cooling is AC from rest of house.

I'm considering digging 2' out under the floor, and sealing the underside with foam. What approach would you take?

Asked By FrankFulton | Dec 21 17
1 Answer

inside connecting walls

Hello again,
I'm still looking for an answer ... Are connecting/joining walls inside the house also double stud?

Asked By BR9 | Mar 21 18
2 Answers

Does Double-stud include all walls,interior and exterior?

I'm interested in finding out more about double-stud green building.
I've looked in several sites, but have been unable to find the answers I need.
Would it be possible for you to clarify for me if all walls are included when double-stud homes are built (i.e. : walls between rooms, hallways and kitchen, dining and/or living areas).
I do understand that all exterior or load bearing walls are double -stud (which that makes complete sense), but what puzzles me is the other walls.
I would really appreciate it if you could clarify this for me.

Asked By BR9 | Mar 21 18
1 Answer

Air sealing vented attic on new construction

Its a mono slope trussed roof, with a vented attic, insulation on the attic floor. I assume I'd air seal at house wrap layer for the walls, but then how would I air seal the attic floor to the walls?

Is it generally better to just go for a vaulted ceiling? in which case I'd probably do SIP over trusses, and air seal the walls to the SIP.

Asked By Bernard Lam | Mar 20 18
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