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1 Answer

What do you recommend for a crawl space vapor barrier?

Its surrounded by frost wall. Wood floor system 2' above. Will 6mil plastic do? How about fastening / sealing to concrete frost wall?

In Green products and materials | Asked By K Greenblott | Oct 11 12
8 Answers

What is the best way to superinsulate a walk-out basement?

I need an expert's opinion of my current and future game plan for my Upstate NY - Zone 6, 1968 back-split renovation.

Q1: Can I safely add 4" of exterior poly iso, since I will already have 3" of closed cell on the interior of the wall?

Q2: How can I improve this plan?

See plan details below.


In Green building techniques | Asked By Alwyn John | Sep 26 12
10 Answers

Will Water Re-Vaporize?

We are having a very difficult time figuring out a WRB for our home in Massachusetts. After reading a great deal about house wraps and learning that condensed vapor trapped behind Tyvek rotted sheathing, we became afraid to use anything but 30-lb asphalt felt, feeling that it was "smart" and "forgiving".

But as we were shopping for Siga tape we learned about Majvest house wrap. We were told that its high permeability would let out trapped water (condensed vapor) because the water would vaporize and escape. Is this so?

In GBA Pro help | Asked By Deb Davis | Oct 2 12
3 Answers

Attic insulation question

I'm doing a gut renovation of a 1000 sq ft finished attic in NJ.

I plan to spray 5" of closed cell foam between 6" rafters and 3" of foam on the attic exterior walls and put 3' x 3' doors on the side attics for access

In General questions | Asked By Bill Winch | Oct 10 12
2 Answers

What is the best type of standing-seam roof for solar panel installations?

I am in the process of redesigning my garage to increase my roof square footage facing south for photovoltaic solar panels. The roof will resemble a "lean-to" and will be 32 feet to the peak and 50 feet long. I plan on using full length sheets to limit seams.

I want the roof to last as I am planning to cover the entire surface. I know the roofing panels will expand and contract with temperature and this can lead to clamps on the standing seam to wear thru the steel.

In Energy efficiency and durability | Asked By Eric Pfeiffer | Oct 3 12
15 Answers

Standard house in Louisiana

Hi, I'm doing a research on single family houses in Louisiana. I'd need to find information on construction methods used for a "standard" house and energy expenditure of an average family living in it. Can someone help me please?where could I look for such information? Thanks!

In General questions | Asked By Elisa Prestia | Oct 10 12
4 Answers

Lightweight insulating (perlite) concrete footing

I'm considering perlite concrete for my basement's subslab insulation. The sub slab will need to be rather thick to get the level of insulation. If I use a 6 to 1 volume of perlite to cement and a 10 inch sub slab I'l get about r15 and have a compressive strength of 125 psi+. Can I simply enlarge the sub slab and pour the walls on it's edge, in effect making the sub slab serve as footings for the wall?
The sub slab will be on top of 6inches of coarse rock covered by poly.

In Green building techniques | Asked By Jerry Liebler | Oct 10 12
70 Answers

Why is there such a bias against fiberglass?

My wife and I are adding a carrage house and I am interested in blowing in fiberglass behind a net. I am planning on building a carrage house and I have been researching the possibility of completing as much of the work as I can.

I am in climate zone 5 and it looks like I can use a product by Knauf called EcoSeal and then insulate the cavity with fiberglass netted. But as I read some of the other conversations going on I am not of the impression that fiberglass is well thought of.

In General questions | Asked By Patrick Hearne | Sep 7 12
8 Answers

Looking for help on a wall system

We are building north of Ottawa, which is zone 6a (I think). Pretty chilly in the winter. We have been given a good quote to frame up our house with typical 2x6 framing, so would like to go ahead with it. The wall system we are thinking of for insulation would be, from outside to inside:

Wood siding
Tyvek over Plywood sheating (taped, sealed)
cellulose or roxul in a 12 inch space
tyvek (taped and sealed)

In Energy efficiency and durability | Asked By jessie pratt | Oct 8 12
5 Answers

What is N-factor?

I was asked by a client -- I'm an Energy Advisor -- what the N factor was for his town requirements, and I didn't know the answer.

In GBA Pro help | Asked By Roland Schoenke | Oct 10 12
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