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

I'm installing radiat tubing in the floor joist cavites of my first and second floor addition.

I've been advised that I need to use aluminum transfer plates with the tubing for maximum support and heating efficiency. I've also had people tell me I only need to attach the tubing to the underside of the subfloor by whatever method, then insulate the top two or three inches of the cavity to insure that the warm air there moves up through the floor, and does not fill the cavity and the ceiling of the room below, wasting heat.

In Energy efficiency and durability | Asked By Todd Audsley | Jan 18 12
4 Answers

Does Green Glue really work for soundproofing? Someone recommended that I use two 1/2 inch sheetrocks and glue them with Green Glue for a media room and that will help. Not sure if you have any recommendations in that regards....Thanks.

In General questions | Asked By Vipin Sethi | Jan 17 12
7 Answers

I have a continuous layer of 1in polyiso on the exterior of the studs, then 2x3 strapping, and another layer of 1in polyiso inbetween the strapping. The stud cavities are rock wool. I have a 6mil poly vapour barrier and then a 2in layer of XPS before strapping and drywall on the inside of the studs.

In my attempt to get a high R value, I didnt fully understand the implications of creating a vapour barrier on either side of the studs. I am now concerned about moisture being trapped in the walls and the rot and mould that goes along with it.

In Energy efficiency and durability | Asked By bryan allemang | Jan 17 12
2 Answers

it says it will cover 105 bf

In General questions | Asked By stan ramires | Jan 17 12
2 Answers

I would like to insulate under my trailer using spay insulation.

In Energy efficiency and durability | Asked By stan ramires | Jan 17 12
2 Answers

We are building a home near Dallas. We are using 30# felt as the housewrap w/Brick construction and Demilec Sealection 500 open cell foam in the attic. We are trying to decide whether to use the same foam in the exterior walls or go with the Blow-in-blanket (BIB) insulation. Do you have any recommendations? Also if you any other thoughts for the attic as it relates to the use of spray foam (or if any other products are better and safer), please let us know. Thanks.

In Green products and materials | Asked By Vipin Sethi | Jan 17 12
3 Answers

We have some T&G paneling that is going to be installed on our walls and ceilings on a house we are building. Understanding that T&G paneling is not an air barrier we have typically installed Sheetrock first and installed our paneling over top the Sheetrock.

Our interior trim salesman says it is better to use OSB or plywood on the wall as sheetrock holds too much moisture and could cause problems with our T&G. He has been selling interior trim for about 30 years so typically trust his opinion.

In Green building techniques | Asked By Danny Kelly | Jan 17 12
5 Answers

We have a project involving a 250 year old house built on the side of hill that, 17000 CFM @50 pascals. The customer does not have a lot of money, so we are trying to figure out the best way to air seal/insulate the crawlspace. When running the blower door, there is noticeable air leakage through the floor boards and along all interior wall bottom plates. The oil furnace is in the crawlspace and although I would like to figure out a way to condition it all, the crawlspace is uneven and broken up by rock walls as part of the foundation, storage areas, and 5 foot high dirt piles.

In Energy efficiency and durability | Asked By Jim Hanson | Jan 16 12
7 Answers

ENERGY STAR (ES) now requires that gypsum wallboard be caulked to top & bottom plates to reduce air movement from conditioned spaces to unconditioned spaces such as unconditioned attics. What are some of the products and practices employed by builders to satisfy this requirement?

In Green building techniques | Asked By Steve Vollstedt | Dec 1 11
6 Answers

I have a bonus room that has accessible 3 walls and the ceiling. The room is already insulated on the walls with R-11 and R-3 foam board. I have had two contractors now tell me that they can spray over the existing insulation with open cell foam vs. removing it. I'm curious as to why it wouldn't be better just to remove all the existing insulation [wall and ceiling], spray foam the back of the drywall between the studs; and then put back up the R-3 foam board on the walls and batt insulation up on the ceiling?

In General questions | Asked By Don Pearson | Jan 16 12
Register for a free account and join the conversation

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