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!

1 Answer

From Designed to Built: Delivering Your Green Home: I read the short transcript of this webinar, since I am currently working with an architect and a "volunteer" builder to develop the plans for a green home of ~ 3400 SF.

The information on your website was excellent and very pertinent to what I am presently doing....is it possible to revisit the actual webinar broadcast which I think was aired in late October and.....when is part 2 scheduled to air?
Thanks, Bob Weber

In Webinar Follow-up Q&A | Asked By Robert Weber | Nov 3 11
2 Answers

I live in a 4-story, 5,000-square-foot, balloon-framed, brick house built in the 1920s or so.

I recently did a pressurization blower-door test on the house and it only reached 20 Pa or so, but I identified some huge places where air is leaking, including the basement ceiling which is open to the floor cavity and 2 closets on the third floor which connect to the attic/outside somehow.

In Energy efficiency and durability | Asked By Karen W | Nov 2 11
10 Answers

Hi - I've just put new attic roof trusses on my house and I am looking to maximize the interior conditioned space available (behind the knee-wall), while keeping the costs down. I reside in southern Ontario.
I would like to do 2lb closed cell spray foam, but, the cost is prohibitive for me.
Can someone please advise if the following is an acceptable layering (from the finished exterior roof looking in towards the new attic space):
- metal roof (with underlayment affixed directly to plywood sheeting)
- plywood roof sheeting
- 1" air gap
- standard rafter vents (to provide 1" air gap)

In Green building techniques | Asked By Michael Davies | Nov 1 11
6 Answers

The reason for my question is that ENERGY STAR states that rigid EPS insulation cannot be used as an air barrier to address thermal bypass unless it is at least 5-1/2" thick.

I posed the following question to ENERGY STAR:

In Green building techniques | Asked By Steve Vollstedt | Oct 30 11
6 Answers

We recently installed a galvalume roof for a client. They asked how the roof was grounded. It's not, as far as I know, other than through the structure. Do others here ground their metal roofs or is it a gimmick?

In General questions | Asked By michael maines | Jun 30 11
4 Answers

We have a cape style house in southern Mass. close to the ocean. The second floor ceiling was low so we took it down and hoped we could have cathedral ceilings to gain some height. I am a little nervous about having this sprayed directly to the underside of the roff. Any thoughts?

In Energy efficiency and durability | Asked By Bill Doherty | Nov 1 11
15 Answers


I own and operate a motorcycle shop. We sell and service motorcycles. Above the shop is my apartment. The only thing that divides my apartment from my showroom and mechanic shop is 5/8 fire rated drywall. My showroom and mechanic shop are split by a floor to ceiling wall with 5/8 fire rated drywall on both sides. During the summer I only cool my showroom and apartment. Leave shop door open during work hours. When winter is here I pull cold air from mechanic shop and heat it (during summer I tape off return and supply vent).

In General questions | Asked By Nick Bulanda | Oct 31 11
5 Answers

I've been interested in rainscreens for a while now but have been looking into them in more detail recently and have a couple of questions.

For context I live in Seattle and while we have (infamously) rainy weather it's almost always drizzle, rather than driven.

I really like the look of an open-gap rainscreen, without a reglet or similar material between each panel. Is this practical, though? Is there an issue of water and/or insects getting between the panels?

In Green building techniques | Asked By Daniel Stewart | Oct 31 11
16 Answers

I used Demilec spray foam for a house I am building in Charlotte NC and we sprayed 5" to 6" in the rafters. When I asked about the issue of how many inches and why we wouldn't do more they referenced a Rescheck Compliance Cert.(sent me a copy) and said 5 to 6" was equal to about 22 to 24 rvalue. The house passed inspection at this 5 to 6". I hear 2 different sides and not sure who is right.

In Energy efficiency and durability | Asked By Chris Helms | Nov 1 11
4 Answers

Hi All,

I have a building envelope vapour management question regarding new construction in 4C (marine, Vancouver BC).

In General questions | Asked By douglas weibel | Nov 1 11
Register for a free account and join the conversation

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