Q&A: A Forum for Green Building Experts and Beginners

[Click map to enlarge]

Please register for a free account or sign in to ask and answer green building questions. The usual rules of courtesy apply: 1. Be nice. 2. If you can't be nice, be polite. 3. If you can't be nice or polite — well, please be brief. To attach a photo or illustration: Under the box labeled "More explanation," look for the words "File attachments." Click that, and you should be able to attach a photo. Thanks for joining the conversation!

4 Answers

Hello,
I live in the Pacific north west, and will be building a home off the cost of Vancouver island this fall. The house is small, 700 square feet, with a 1 n 12 pitched roof as the design. We have not started construction on the house as yet and we want to deal with the roof in a way that will, of course, provide the best of all worlds.

Asked By Jeannette Sirois | Sep 1 14
3 Answers

So I read the innie vs. outie window article on GBA and decided to go with the innie route as I had already made my R/O to size and didn't have time to fir out the windows before my window installer (friend) showed up. So I have my windows in with flanges against sheathing and they stick out just over 2" from the sheathing. I am putting 2' rigid polyiso on the exterior and butting it into the windows. This means there is no foam showing. Do I need to put peel and stick flashing on the exposed foam before installing it? should I leave it away from the window slightly and spray foam that gap?

Asked By jordan Saunders | Sep 1 14
20 Answers

I was speaking with my passive house consultant the other week, and she expressed concerns about boring critters and subsurface rigid insulation. She had such an experience with some insulation in her garden (It was put in one season and removed at a later time as she got back to completing the project.)
Now, I know all about the ate/termite protection used in these insulation products, but what about larger critters that would love to have a warm dry home?

Asked By Steve Young | Aug 16 14
8 Answers

Hi,
I am currently redoing the exterior of my house with a new vinyl siding and changing all windows. My house was built in the mid 80's and have 2x6 studs with Batt Insulation and mostly without a vapor barrier... but the insulation is not great, especially the air goes through the house.
My question is what is the best insulation for me to put outside the house underneath the vinyl siding. My windows will allow me to go up to 1 inches of exterior insulation.
So XPS with Typar? Polyisocyanurate (IKO Ener Air )? Others?

Asked By Jason Haché | Aug 29 14
18 Answers

Hi. I am back and forth on whether I should use XPS (blue board) or EPS for the insulation underneath my slab. I understand the qualities of each regarding water absorption and drying out, but would it (XPS particularly) affect the long term performance to the point where the slab is compromised? I also understand the pollution associated with XPS manufacturing. I have the option of purchasing 6" (house in very cold climate) of EPS (R-24) or 4" of XPS (R-20). The EPS is less expensive per inch, however, I need to pay for shipping which jacks up the price.

Asked By Matthew Michaud | May 2 14
3 Answers

Hi folks, great site.

I have a crawlspace in a new house that smells of chemicals. The dirt floor is sealed with a vapor barrier and the walls have Spray Foam Insulation. The space is pretty airtight.

My ERV was installed incorrectly (another story) and sometimes the smell from the crawlspace comes up into the house. Makes my eyes burn, and it gives me a headache. Hopefully that will be fixed this week!

Should I be able to smell the foam 2 months after it has been installed?

Asked By Brett Michaels | Sep 1 14
11 Answers

My designer and I are designing a house as close to passivhaus standards as we can get. We have agreed to design it with SIPs but he thinks a truss roof with spray insulation would work just as well. I'm thinking a SIP roof eliminates potential for thermal bridging and is less costly to install versus the truss roof.

Asked By scott schroeder | Aug 29 14
5 Answers

Most of the blower door tests that are mentioned on GBA give numbers under 3 or 2 or 1 ACH50. I'm guessing that none of these homes have a traditional fireplace. How much does a traditional fireplace with standard chimney damper contribute to air exchange numbers? What are some recommendations for improving a house with fireplace and chimney?

Asked By Derek Roff | Sep 1 14
5 Answers

I am replacing my existing siding and I am doing the following -stud - 5/8" plywood - 1-1/2" of Polyisol, 3/8", WRB, rain screen, fiber cement siding. The house is in the San Francisco bay area on a hill with a stepped foundation.

Asked By Randy Mason | Aug 30 14
3 Answers

Wondering if the arctic wall design would be appropriate to use as a roof/cathedral ceiling here in CZ6 upstate NY. There is a comment about it on Martin's blog, but I didn't see any discussion : http://www.greenbuildingadvisor.com/blogs/dept/musings/how-build-insulat...

from inside out it would be:
GWB,
2x4 service cavity,
1/2" CDX taped and sealed,
parallel chord trusses 12-12 pitch dense packed with cellulose,
vapor open WRB (suggestions for best product welcome),
2x4 furring,
5/8 sheathing,
felt,
asphalt shingles.

Asked By Trevor Chadwick | Sep 1 14
Register for a free account and join the conversation


Get a free account and join the conversation!
Become a GBA PRO!