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4 Answers

Sub-slab drainage stone size

I know the typical recommendation is 3/4" no fines. Foundation contractor and stone supplier are recommending I use 1.5". Foundation contractor is trusted and has used product a great deal including under some very dry basements that I've been in. Stone guy says he has 3/4 no fines - but it's more money for no gain. I have seen the product they are calling for; it's a mix of ragged and round stone that would surely drain very well. I can tractor stone in, so will be able to minimize trying to stick a shovel in it. SDR 35 interior footing drains.

Asked By Jim Tyler | May 13 16
1 Answer

Patio roof on top of insulated roof detail?

Zone 4A, hip roof with 4:12 pitch; spray foam insulation to be on the interior side of the roof deck (not ventilated). I will be adjoining a new roof out over a patio, placing the new ridge and rafters on top of the existing zip sheathing . The patio roof will have exposed rafters, and the wall of the house will extend up to the new ridge, so the part behind this vertical wall that joins with the existing roof will create a dead space.

Question: is the dead space between insulated roof deck and addition an issue?

Asked By David McNeely | Apr 29 16
5 Answers

Is this wall assembly okay?

I live in upstate SC in climate zone 3. It would be more like 3.5 if such existed. I'm about to build a house and the wall assembly I want to use is slightly different than examples that I have seen and I'm concerned about drying/dew point.

I plan to use 2x4 wall construction, wrap it with 2" of rigid Roxul abd 1/2" Zip sheathing with a brick veneer. My thinking is I have a standard 6 9/16" window/jamb width but I have also killed the thermal bridging.

Asked By Chip Radford | Apr 26 16
1 Answer

Update on polyiso as a WRB?

Martin did an article on Using Rigid Foam As a Water-Resistive Barrier back in Sep 2010. In it he brought up the possibility that polyiso might shrink over time, so might not be reliable as a WRB even though rated for WRB use. Hoping that 5.5 years later there is enough new information for an update on best practices and practicality of utilizing exterior polyiso as a WRB.


Mitch Costa

Asked By Mitchell Costa | Apr 22 16
4 Answers

Unvented cathedral ceiling condensation issues

Hi there,

I received a call form one of my Architect clients. His friend recently re-built his roof and now has major condensation issues; so I went to take a look. Here is the constructed assembly as best as I can figure, pictures attached.
Inside to Outside
1. Heavy timbre with wood cladding in between
2. 6mm poly that wasn't removed attached to the heavy timbre's with acoustical sealant and staples
3. From here the old roof was removed from the outside. Between the heavy timbre's polyiso was tuck taped to the timbres to give the foamer something to spray against.

Asked By Kristopher McMenamon | Apr 18 16
4 Answers

Can I get the name of an appraiser in the New Orleans area who is appraises homes with "green" technologies?

I am getting ready to sell my home. I live in Mandeville, Louisiana, right outside of New Orleans. I want to get my home appraised, and would like to have someone who knows about green technologies. When I built my cottage six and a half years ago, I used as many green technologies as I could afford - foam insulation, a white metal roof, Hardy board, trex on the porch and deck, etc.

Thanks for any information that you can provide!


Vera Clay

Asked By Vera Clay | Apr 17 16
1 Answer

Can I insulate inside cavities after drywall is up?

I live in a colder climate in a home completed in the 70's. The former owner put drywall up in the basement without insulating in some spots causing cold infiltration. In other areas the wall cavities are only partially filled with fiberglass batt insulation - again leaving cold gaps.

Is there anything I can do to better insulate these areas without having to remove the drywall or the outside cladding on my basement walls?

Asked By Carl Dillon | Apr 18 16
8 Answers

Low/No-VOC PVA glue and Caulk

Hi there,

Just want to be sure I'm not missing anything ---from the reading I've done, it seems that most PVA woodworking glues are fairly nontoxic...We have specified no or low-VOC products for our remodel, but our contractor is not an expert in this area. They want to use Titebond II. It seems like a safe choice. Does anyone agree or have a better suggestion for a carpenter's (wood) glue -- aiming to have a minimal impact on indoor air quality--very limited off gassing.

Asked By Mindy Munger | Aug 14 14
33 Answers

Spray foam insulating

I have a home that is approx 800 sq ft in size not counting the attic.
I'd like to spray foam it.
It is about 70 years old built with 2x4's.
Crawl space, no bsmt.
A little over 8' walls on main floor ( 100")
I was planning on doing 3" of closed cell 2LB spray foam from a professional.
Also, as well in the rafters since it is a sloped roof but I'd like the attic finished since it is 7ft high, I would have some nice, temp regulated storage and I am planning to install the furnace there too.

I was then made aware of certain concerns.

Asked By mic l | Apr 16 16
11 Answers

Zone 7A existing cabin crawl space headaches

We recently purchased a existing seasonal lakefront cabin built in the 80s in northern MN. We are remodeling and converting to all-season occasional use and trying to address the vented crawl space. It is damp and there is some mold on floor joists, but I don't believe there has been standing water and the soil composition is sand. The problem is access: there is very low clearance in most areas (only 6-8" in some spots). Our contractor has proposed 1) adding rigid insulation to the perimeter block foundation, or 2) raising the cabin and adding two more rows of block.

Asked By Deb Edwards | Apr 13 16
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