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

Has anyone heard or experienced any down side to using pumice as a building material for the floor or walls?

I am thinking of building with a 12 part pumice to 1 part cement mix as wall material with standard 3 layer stucco cement as wall covering . I heard New mexico pumice had possible radon emissions ?
I am wondering about moisture condensation inside of wall at the dew point leading to mold ?
I live in western oregon with high humidity ,the pumice would come from our abundant pumice fields.
pumice can't rot can't burn and has 1.5R per inch .
The only down side I see is there are no codes for pumice and would need to get an engineers report for earthquake stability using rebar.

Asked By keith schneider | Jun 25 10
3 Answers

New home questions

I plan on retiring to BC in a few years and building " a pretty good home" . I have been reading almost everything on the GBA web site, very informative. Really appreciate all the blogs by Martin and all the others .

Asked By bert matter | Mar 4 15
6 Answers

Airspace for solar barrier

I am adding a solar barrier between layers of an alluminum roof. The existing roof is over a covered florida room. The roof system has a lower layer that is also the ceiling. The lower layer is connected to the top layer by 3 inch alumuinum I beams. The roof is insulated with porous styromfoam which is noisy when it rains and does not stop any heat penetration at all. Impossible to aircondition! I purchased a solar barrier to place between the layers of room.

Asked By Phillip Ragan | Mar 4 15
3 Answers

Vented & unvented in same roof plane?

Hopefully you can all see this attached glass-house view of my proposed roof.


The open attic at the bottom right of the photo allows plenty of room to super-insulate, same too with the open attic above the 2nd floor ceiling, up in the top left/center of the photo. The sloped roof though poses a problem for super-insulation levels, just not enough depth. What I'd like to minimize is a path of least thermal resistance which would circumvent the high insulation levels in the open attics and favor "Easy" migration through the sloped roof section.

Asked By Alex House | Mar 3 15
1 Answer

How can I super insulate, air seal, and vent this space?

This is the top floor of my new to me house in zone 5. Under which is a fully insulated living space of 12 years. So right under that decking is standard 10 in fiberglass..

Asked By stephen edge | Mar 5 15
1 Answer

I am overwhelmed with the wall cavity options and need advice

After researching for the last few months on this website, buildingscience.com, and PHIUS.org I am just overwhelmed...buy maybe under informed. I am an owner/builder (former construction project manager...mainly responsible for foundation and electric work then) and this will be my second house. Most of the case studies and articles I have read are about homes in climate zones far more extreme than what we typically have in TN.

Asked By Andrew Bennett | Mar 4 15
1 Answer

24" o.c. rainscreen furring concerns

Getting ready to start a house for a customer, double 2x4 walls, etc. We left the exterior side 2x4 @ 16" oc due to rainscreen furring concerns.

I'm beginning to question whether we can move to 24" oc on the outside wall and use our rainscreen furring 24"oc...?? Furring will be 2x4 KD lumber, mainly because we can get 2x4 cheaper than 1x4 and it's not that much more effort.

So can the furring go to 24"oc and not have problem with the clapboard siding going crazy?


Asked By RMills Miller | Mar 4 15
5 Answers

Insulation around a center chimney -- cape?

How would one insulate around the chimney in the attached pics? Would I start at the ceiling and just put a bunch of Roxul around it? How could air sealing work? Fireblock foam?

Bonus question: Is it too late to double stud these walls?


Asked By stephen edge | Mar 4 15
11 Answers

Plans Review with a few questions

We are getting closer to building our new home. The preliminary drawings have been completed (links to plans at the bottom). We aren’t exactly building a green house, but over the last year I’ve read an enormous amount of good information from this website and a few others to help guide me in building a more durable and energy efficient house than what is typically done around here (vented crawlspaces and ducts in a vented attic are pretty standard here).

Asked By Michael Geoghegan | Feb 4 15
0 Answers

Energy Efficient Home - A Few Things you'll Be Able To To Save Energy At Home

When referring to home improvement, one belonging to the first questions that it is advisable to ask yourself is if you're planning on selling the house soon. In case the answer is yes, then everything you actually do should be solely market the of your house focus only on the critical maintenance items and the areas with highest presence. If you are not selling soon, then five more leeway to design in a way that is better to really taste.

Asked By Palma Galloway | Mar 4 15
Register for a free account and join the conversation

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