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1 Answer

Duct-free bath fans?

Does anyone have experience with these?

Do they satisfy the IRC 2009 code for a powder room (just toilet & sink)?


In Building Code Questions | Asked By Kevin Dickson, MSME | Nov 14 12
2 Answers

Framed basement wall - what sheathing to use?

Hi, my builder proposes the basement end wall (10 ft. high) to be framed and covered with stucco to match the concrete side walls. He says to frame it vs. using concrete may cost a couple of $thousand less. The basement will be uninsulated and unheated.

Problem is what to use for sheathing that doesn't offgas. That excludes OSB and regular plywood. DOW SIS? Marine grade plywood? Advantech? I guess the same goes for the unvented attic sheathing, but maybe not as much of a concern (blown-in FG there). Does anybody have any other suggestions? Thanks much.

In Green products and materials | Asked By Ed Siff | Nov 10 12
8 Answers

What kind of rigid foam insulation should I install over existing plaster walls before installing new sheetrock?

I have an older house with very little insulation and lots of cracks in the plaster. I would like to insulate by putting a layer of foam board over the plaster, and then covering the foam board with sheetrock. Are there any problems with doing this? I want to use a foam board that is green with no off-gasing.

Thank you,


In General questions | Asked By Paul Smith | Nov 11 12
3 Answers

Water and Polyiso Foam Sheathing

If I were to use polyiso sheets to insulate a basement wall and the basement eventually flooded, what would happen to the polyiso?

Also, I'm considering using polyiso sheathing on a new house for the 1st time instead of XPS. What happens to the edges of the polyiso when exposed to rain (potentially heavy rain or days of rain) while under construction?

Bruce Miller

In Energy efficiency and durability | Asked By Bruce Miller | Nov 12 12
2 Answers

Would the following method of finishing a basement cement wall cause any mold issues?

Someone suggested to lay 2x4's flat against cement wall every 24" and secure with adhesive and nail gun. then put 1.5" XPS rigid foam insulation in that 24" space against cement wall. Finally cover wall with 1/2" regular sheetrock. What about using pressure treated 2x4's? Would the chemicals cause more health issues?

In General questions | Asked By Tim Sexton | Nov 13 12
3 Answers

Best Options for Retrofit of Heating System?

We have a oil burner/hot water radiator heating system in a 1500 sq ft house that is approximately 60 years old. This system also provides the hot water for the house. Furnace is probably 15 years old and appears to be ready to fail. Also have AC and duct work for first story which is probably at least 15 years old as well. Rarely use the basement, but it does have one radiator for the hot water system.

In Mechanicals | Asked By Jeff Lucas | Nov 13 12
4 Answers

Is veneer plaster considered an air seal?

I run a remodeling company in Littleton, MA that has become very focused on builiding envelope efficiency and durability. We (myself, project develper, production manager, and project supervisors) are working on standard specifications for air sealing and as we were discussing interior air sealing, one of the project supervisors asked if sealing the perimeter of the wallboard at inside corners was really necessary if we were properly sealing the framing joints behind the wallboard and skimcoat plastering all those inside corner joints.

In Energy efficiency and durability | Asked By James Basnett | Sep 5 12
38 Answers

AECB Website and Point Thermal Bridges

Some interesting thoughts about thermal bridges in this document.....

"Point thermal bridges -.....the nails, screws and other fixings in timber-frame construction."

My Question is Concerning Outsulation Strategies.....
What is the thermal effect of the 100's of large "nails,screws and other fixings" that penetrate the outsulation and terminate in the studs and plates( which are also thermal bridges)?
In other words...a thermal bridge connected to a thermal bridge.
Is it significant?

In Green building techniques | Asked By John Brooks | Oct 12 09
4 Answers

Half wall basement ?

I priced spray foam and it was 3k so we want to use xps on the block walls and in the rim joist area. Since the 2x4 walls are only 1/2" from the block wall I can't fit any foam back there can I cut the foam to fit between the studs and fill the area behind the stud with canned foam?
Do I caulk the sill area or foam it?
The area above the block wall is the above grade wall and it has fiberglass batts and is 2"x6" framing then the 2"x4" frame is in front of that to make a flat wall to the ceiling how should this upper wall be insulate? XPS? Fiberglass a combo and how much R-value?

In GBA Pro help | Asked By Kelli Cornwell | Nov 11 12
3 Answers

Does a vapor barrier belong above my steel ceiling in heated shop?

Having been nicely schooled on reasons not to put vapor barrier on my walls with exterior foam in zone 6, SE MN, I now wonder about the proper way to insulate the ceiling. This is a heated shop with a vented roof and scissors trusses. I would like to use ribbed steel panels for the ceiling, and have been given rolls of R38 unfaced insulation that I would place on top of the steel panels.

In General questions | Asked By Kent Jeffery | Nov 12 12
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