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7 Answers

Floor Slab: Is a Vapor Barrier Needed with Rigid Foam?

If one is using 3" of rigid foam (EPS) underneath a 4" slab-on-grade, does one still need to install a vapor barrier?

Here is the build-up from the ground up:

4" compacted AB
3" EPS (termite treated)
4" concrete

Asked By Peter L | Apr 18 15
0 Answers

Densglass & Stucco

Can one apply EIFS or stucco directly to DenGlass or does one need to treat DensGlass like wood/OSB sheathing?

Can DensGlass be used on a soffit with it directly being applied to the OSB sheathing?

Asked By Peter L | Apr 19 15
5 Answers

Do I need an interior vapor barrier of some sort?

The house was built in 1991 and is located in SE Mich, Zone 5?

It currently has a wood composite siding, no housewrap, and a mixture of plywood and double foil-faced foamboard (no discernible pattern). The studs are 1x4s. On the inside, it had fiberglass with a plastic vapor barrier. The windows are flangeless wood windows that I plan on keeping and restoring.

Asked By Hedy O | Apr 17 15
6 Answers

Vented SIP roof — fascia detail

Trying to find a photo or a detail of a vented SIP roof fascia area. Typically they use 1x or 2x furring strips on top of the SIP and then the layer of sheathing and roofing material. How the fascia gets finished is something that is hard to find. There is a 1" or 2" vent gap there so how does that all come together?

I did an internet search and could not locate any such detail.

Asked By Peter | Apr 16 15
20 Answers

Roof furring questions

When it comes to furring a roof, are 1x3 or 2x4 furring strips better to use? I assume the latter because they are stronger/wider and give a better grip area to the sheathing above. Spacing should be what: 12" or 16" on center?

My other question is with the sheathing above. I read that plywood is better than OSB although there has been a lot of problems at the lumber yards with plywood cupping. The lumber yard attendants said that the QC on plywood is really bad because it is so rarely used. I assume 5/8" sheathing is ideal for a metal roof?

Asked By Peter L | Apr 6 15
4 Answers

Double stud wall with timber ceiling

I am designing and building a double-stud wall, single story house on a slab-on-grade foundation with a frost wall. As a dedicated timber framer, I have tried to hold on to some aspect of that approach while acknowledging that it adds cost and complications with air-sealing, etc. I devised a method where the outer wall supports the roof (cathedral) and the inner wall supports the ceiling assembly. My concerns are with the inner wall bearing the load from the floor to the edge of the slab.

Asked By Caleb Creaven | Apr 8 15
8 Answers

I need assistance with window/door install with 4" foam

I am looking for some direction on installing windows and doors. I have 4" exterior EPS on a 2x6 walls

The current plan is to build 5/8" plywood boxes (I believe they are called Dewey boxes) to get the nail fin of the window to the same plane as the furring strips that the foam and the siding will be attached to.
I am sure its been covered but searching Dewey box got me 0 results so I wonder if someone could point me in the right direction?

Thanks
Tim (Kenora ON Canada zone 7)

Asked By tim brown | Mar 28 15
3 Answers

Rigid foam over roof sheathing & spray foam interior

I was just reading Martin Holiday's article about rigid foam over roof sheathing and saw that closed cell foam under the roof sheathing was not recommended. Our house has 3" of closed cell foam underneath the sheathing and we were hoping to apply a layer of rigid foam externally in a future roof replacement. What is the reason this is not recommended?

Asked By Josh Wimpey | Apr 5 15
3 Answers

Roofing - Mechanical seam vs. Snap lock

For a standing seam metal roof which is the better system to install? The Mechanical Seam or the Snap Lock system? Both have hidden fasteners but which system works better?

Asked By Peter L | Apr 6 15
2 Answers

Rigid form on interior wall surface

foam insulation on interior side of the wall

Asked By Jim Reed | Apr 5 15
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