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1 Answer

Optimum air gap for skylight

Context: a 14x7x6' tinyhouse with 4"-thick polyiso insulation on all surfaces except the windows, which, for reasons that aren't relevant here, must be on the roof.

Several hours of research shows that the optimum air gap for a typical double-glazed window ranges between 13-30mm depending on whom you ask. Charts show that U-value tends to bottom out at around 13mm and slowly climbs up from there. From this research I've gleaned hints that the glazing material and the angle the window is mounted at are factors, but I've been unable to find out how they matter, so I turn to the Community.

Asked By Geva edhrven | Dec 8 16
5 Answers

Converting a 1830 House to a Super Insulated House

I am diving into the insulation in my 1830 Farm House, 1500 sqft, which is located in upstate NY. I am looking to retro the house into a tightly insulated house that will ultimately heat off of electric heat or heat pump mini splits. I just had 10kw Solar system to create the electricity for the heat. The solar system was designed to cover 110% of our projected electrical consumption with a mini split system running. My goal is an 1830 super insulated house.

Asked By Larry Broderick | Dec 7 16
2 Answers

Exterior Rigid Foam Under Sheathing?

In my local area there is a green building consultant that recommends a CI panel which is basically EPS foam glued to OSB. The way this is installed would be the OSB to the exterior. Almost every house I see with exterior rigid foam in my online wonderings is covered with blue and pink XPS, the OSB sheathing is nailed directly to the studs and is completely covered with the rigid foam. This leads me to the following questions:

- Is anyone familiar with these kind of CI panels?

Asked By Joshua Greisen | Dec 8 16
0 Answers

Double interior rock wool

Working on plans for my next home. After lots of research on here and others I am considering the following wall assembly. From the exterior... wood siding, tar paper, 1/2" plywood with taped joints, 2x4 ,16 on center wall stud with roxul, uniterupted layer of 1 1/2" comfort board, layer of a variable perm vapor barrier (taped seams and such), then a layer of 2x3 installed 2 ft. on center as battens for electrical with shallow boxes , second layer of comfort board fit between the battens, drywall finish. I am in zone 5 in northern ct.

Asked By scott mangold | Dec 8 16
1 Answer

Moisture where ceiling and walls meet on exterior walls

Hi I recently read a article on here talking about my exact problem and that someone had did a study to fix it , I was having trouble completely understanding if the three things they did worked at all? One was insatlling 6 inch insulated crown moulding in the interior of the house. I can't find it for sale anywhere and I read another article that some guy used 6 inch mdf crown moulding and drilled holes in it and sprayed great stuff into it but he never said if that fixed his issue or not.

Asked By Patrick Conry | Dec 8 16
15 Answers

Is this a reasonable solar bid? — and other questions

Howdy folks,
I got my first solar bid today, from Consolidated Solar Technologies. For a 3.2 kW ground-mount array in Albuquerque, New Mexico, the total cost before the federal tax credit is $16,300, and $11,410 after the credit. This works out to $3.56/watt.

One thing I worry about is that their calculator shows a higher projected output than PVWatts does. Their tool showed 6,500 kWh yearly, but PVWatts shows 5,844 kWh. This is supposed to be a net-zero-enabling array, so I don't want to underproduce. I'm using 6,500 kWh for my yearly usage

Asked By Nate G | Dec 5 16
2 Answers

Insulation options to add R-value

I had the opportunity to reroof this spring and add exterior rigid foam. I used foil faced polyiso 2.75" thick. Due to time and money constraints I applied a single layer taped and foamed. Through fastened wth .5" OSB cut into 3" strips. A new OSB deck was installed and asphalt shingle roof on top of that.

Asked By David Mosijchuk | Nov 23 16
3 Answers

Batt insulation

I'm in the process of buying a home (Metro New Orleans, Zone 2A, very warm and moist) for my daughter and noticed the attic insulation was installed with the Kraft paper facing up. That problem is being corrected by the seller, but now I wonder if the wall insulation was installed incorrectly as well. When given an opportunity to re-inspect this coming Monday I will be removing electrical covers and other things to see if the insulation problem continues with the outside or exterior walls.

Asked By Bill Stretzinger | Dec 6 16
9 Answers

Can this assembly work for a flat unvented wood roof in Atlanta, GA (Zone 3)?

Hi all, I am building a flat un-vented wood roof in Atlanta, Ga (Zone 3) and I want to make sure I am doing it correctly. The assembly that I have so far is:

-TPO roofing
- 1/4" exterior grade drywall cover board
- 2.5" Tapered insulation
- 4" Rigid tapered Insulation
- 2" Rigid Insulation
- Waterproof Coating on osb / or peel and stick waterproof membrane
- 5/8" osb
- 2x10" beams (all at the same height)
- 2" closed cell spray on foam insulation
- 1 layer 5/8" type x Drywall
- Resilient channels
- 1 more layer 5/8" type x drywall

Asked By A Patel | Dec 6 16
6 Answers

Exterior foam application and window details

Im in Phoenix about 6 months away from starting my build. I was thinking about upgrading my exterior foam from 1.5" to 3" EPS. The window detailing is where my question lies. I've read the articles here, but we will be using mostly EFIS for our exterior cladding (with some stone veneer). My thought was to nail the window to the exterior after the OSB and Tyvek stucco wrap just like you would without using foam. Then add the 3" of EPS right up to the edge of the window and just add the EFIS to the 3" return created. For the stone veneer we will just frame out the window the 3 inches.

Asked By Jeffrey Savage | Dec 6 16
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