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2 Answers

What type of interior insulation with 1" exterior rigid foam?

I had a strong hand in the design of my new home. However, I was a newbie when detailing the exterior wall details and we only put on 1" of exterior rigid foam. I now wish we would have done 2", but it's too late to change. We are currently planning on installing closed cell foam as interior insulation, but I just heard Martin speak on the Fine Homebuilding podcast and he says that rigid foam on the exterior and closed cell foam on the interior is a dumb idea. We live on Cape Cod, have 2x6 exterior walls with plywood sheathing, a liquid WRB, the 1" XPS foam, a rainscreen and cedar shingles.

In Energy efficiency and durability | Asked By Holly Trick | Jun 8 18
7 Answers

OSB as air barrier

I read the relevant GBA article, and the entertaining comments section (which left me perhaps more confused than before. Since that is a pretty old article, I'd like to ask if there is any updated info. What is the latest opinion on it? Were the air leakage failures ever determined to be manufacturing defects or an inherent problem with OSB? My house was built with 7/16 OSB interior sheathing as the air barrier / vapour retarder. I'm finally getting close to putting up drywall, and wondering if I should do anything else before it's closed up.

In General questions | Asked By Trevor Lambert | May 31 18
6 Answers

Brick veneer soffit gap: block and drill weep holes?

Background:
Common scenario, but I searched the internet for hours and somehow couldn't find this answer. I'm very slowly working on insulating and sealing our 40s brick veneer house, Cape 2.5 story with slate roof and no overhangs.

In Energy efficiency and durability | Asked By BryanBL | Jun 7 18
3 Answers

Shingles over rainscreen over Roxul

Any tips on installing shingles (cedar or fiber-cement) over a rain screen, which is installed over 1.5" of exterior mineral wool? I was thinking vertical furring strips fastened to the studs, then horizontal furring strips on top of those to provide a shingle nail base. Sounds like a lot of extra work but the only other way I've seen (in one of Martin's articles) is to install horizontal strips with dado cuts on the back, which sounds like even more work.

In Green building techniques | Asked By Phil Boutelle | Jun 1 18
3 Answers

How crazy is my plan to circulate air in 350 sq. ft. of space with closed doors and no windows?

I'm working on a 650 sq ft office suite located in Los Angeles. The space is split roughly in half: two therapists offices (windowed) take up one half. A waiting room, hallway, bathroom and kitchenette (none windowed) take up the other half.

The therapists offices currently have in wall ACs that are too loud for therapy. We're looking at Ductless ACs as an alternative but the budget only allows for a Dual Zone system. The indoor units would have to go in the therapists office, there is really no alternative here.

In GBA Pro help | Asked By TB93 | Jun 8 18
7 Answers

Nits & grits redux

SPECIFICATIONS:
Climate zone 3A (Atlanta, GA)
3 levels with basement walk-out to rear
Bonfiglioli wall
2x6 studs
Batt insulation in 7.25" cavities, type TBD
Plywood sheathing
Seams taped, type TBD
Housewrap lapped, type TBD
No exterior insulation
Air gap to majority brick exterior wall veneer
Rainscreen to minority fiber cement siding
***VENTED UNCONDITIONED ATTIC***
Fluffy insulation above upper ceiling, type TBD
Site-built roof frame, 5:12 hipped upper roof with some 3:12 lower level roofs
Plywood sheathing roof deck ***NO INSULATION***
Peel & stick lapped, type TBD

In Energy efficiency and durability | Asked By PJ Clem | Jun 8 18
9 Answers

2x6 stem wall detail options

Hello everyone,

I'm in the early stages of designing my future home and ran into a situation where I'm looking for some input. I'm wondering what the best option for me would be at the intersection of the radiant floor slab, foundation stem wall and 2x6 exterior wall. I've attached the 3 options I'm considering.

In Plans Review | Asked By Sturg | Jun 7 18
7 Answers

Rain Screen: Horizontal furring strips with corrugated metal siding installed vertically

I am installing corrugated metal siding vertically over 1" Roxul Comfort Board exterior insulation, thereby necessitating a horizontal furring strip that can bear the weight of the siding. We originally furred the windows out by 2 3/4" with the idea that we would use 1 x something vertical furring strips to allow drainage, then 1 x something horizontal furring strips for the metal.

In General questions | Asked By Amy Hazeldine | May 28 14
5 Answers

Flat roof attic venting

My first question is.... can anyone recommend a home energy expert local to me in San Francisco Bay Area (zone 3c)?

My 1100 sqft flat roof has both roof joists and ceiling joists with blown-in cellulose filling the ceiling joist cavity, and about 15" of space between joists. I have 2 soffits (about 6x12" each) on one side of the house, one skylight is permanently vented and overlaps with attic space, and there is a louvre vent in an interior closet (which doubles as access hatch).

In General questions | Asked By DAVID BIANCO | Jun 7 18
1 Answer

Crawl space remediation

Young, dumb and broke, we built the original part of our house (CZ6) on pressure treated piers over bare ground 35 years ago. The floor was insulated with R-19 fiberglass covered with OSB. A few years later we replaced the piers with a shallow concrete block perimeter wall. The exterior from footing to house sidewall was covered with an inch of poly iso protected by a layer of pressure treated plywood.

In General questions | Asked By Ron Rosen | Jun 7 18
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