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!

2 Answers

Is anyone aware of a prefab soffit insulation baffle that offers a 2" chute opening? Fine Homebuilding had a recent article in which Joe Lstiburek indicated that a 2" airspace in the vent chute should be the minimum as opposed to 1" per code for best performance. A product from AccuVent was shown in the article, but it doesn't achieve that 2" opening. Are there any prefab alternatives available that do? If not, is there one that gets close? Thanks.

In Green products and materials | Asked By Milan Jurich | Feb 11 12
30 Answers

I design/build homes in a Cold Climate area in WV with an average yearly temp. of about 45 degrees F.

I have read about a few new Cold Climate Heat Pumps that have come on the market in the last few years. Unlike conventional Heat Pumps these new models claim to perform effeciently below freezing temps. I believe a company called Nypl as well as a company called Hallowell have models available. I have read that the Hallowell Acadia model offers a Coeffecient of Performance of 2.55 at 17 degrees F.

Do these Cold Climate Heat Pumps truly perform as advertised?

In Mechanicals | Asked By Joseph Garten | Apr 3 09
5 Answers

I was talking to Dr. Joe the other day and he made us an offer we could hardly refuse. He wants to give a class on Renovation and Restoration open to GBAGreenBuildingAdvisor.com PRO members only. He's also offering a 10% discount off the normal price ($395), making the price ($355). We are thinking sometime in June.

If you'd be interested in attending this class, please click through this link and check the appropriate box -- we want to gauge interest to see how big a room to get.


In General questions | Asked By Daniel Morrison | Feb 10 12
1 Answer

I live in zone 2B and have an old house with no insulation in the attic. I have no wiring, plumbing, or ductwork in the attic and it is unvented. Advised to spray open cell foam on the attic floor between ceiling joists (2X4 on 24 inch centers). Was hoping 3 layers of blue Dow board with foam around edges between joists to air seal space and provide moisture barrier and then loose blown cellulose on top might work almost as well but for less$$. Please advise.

Paul in Texas

In GBA Pro help | Asked By Paul Hanslik | Feb 10 12
1 Answer

Central coastal California area. The addition is on the north side of the existing house. I want to know the environmental hazards and the human hazards that may exist. The room has a vaulted ceiling and the area is 7 1/2" deep. The proposed agent is LD-C-50 ICYNENE spray foam.

In Green products and materials | Asked By mondra randall | Feb 10 12
3 Answers

We are building a new home in NW Montana, zone 6. We have a great room with a vaulted ceiling and a vented roof above. Going to use cellulose to r49 above great room. I want to make sure that I get the ceiling profile right. I have been told to put poly on ceiling then osb or plywood and lastly the metal we want to use for the interior finish. Will this work without causing moisture problems?

Any draw backs to using metal roofing on the interior ceilings as finish?


In Energy efficiency and durability | Asked By Rod Cleveland | Feb 10 12
4 Answers

We are trying to decide on window glazing options for our east facing windows in San Francisco. Our window manufacturer uses Cardinal glass and offered us two Low-e options.
Low-e 277 and Low-e 180.

In Energy efficiency and durability | Asked By Donovan Corliss | Feb 9 12
4 Answers

I am wondering if anyone has any advice on properly flashing window and door penetrations when using a panel type siding. My specific project specifies LP Smartside reverse board and batten siding in 4x8 sheets. The windows and doors are aluminum clad, with a 1x4 picture frame trim detail.
I am mainly concerned about the detail at the head, where it should be flashed. I would like to avoid just cutting out a hole in the panel for the trimmed and flashed unit, then relying mainly on a caulk joint, but maybe properly detailed, this is the simplest option.
Thanks for any help.

In GBA Pro help | Asked By Pete Archer | Feb 9 12
9 Answers

Hello to all,

Well here is my conundrum. I live in a house that was built in 1983, and it was built using the minimum materials in every aspect. The house is a modern/contemporary with vaulted ceiling up to 28' high. Saying that the roof was framed using 2x8 rafters, and yup r-19 insulation faced bats. The walls are 2x4 with what seems to be at best 4 mil vapor barrier, r-11 unfaced bats, and 1/2" Celotex w/5/8" t-111 exterior siding.

I need to bring the r-value up to as (close) to minimum code. Our local code call for r-38 ceiling, r-19 walls.

In Energy efficiency and durability | Asked By jason hood | Feb 8 12
4 Answers

I am looking for a very energy efficient way to build a house and to avoid all mold issues inherent with plastic wrapped houses that can't breathe. Living with mold greatly increases symptoms of Lyme disease.
Got any suggestions?

In Green building techniques | Asked By Margery Brache | Feb 8 12
Register for a free account and join the conversation

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