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10 Answers

I'm building a house in zone 6a, Central NH. My plan is to wrap the house with 2 layers of eps totaling 4.5 inches with the joints staggered. The framing is 2x4 and no interior vapor barrier will be used. I was planning to add 3.5" of fiberglass to the cavities.I'm using DuPont drainwrap over OSB with the joints and stud lines taped with zip tape. The foam will be furred vertically with 3/4" boards to ventilate behind the siding.

In Energy efficiency and durability | Asked By Nate Weiner | Jan 13 12
5 Answers

We provide new statistical evidence to show that energy efficiency policies and programs can reliably cut energy use—a finding that is consistent with the policy stance of leading experts and organizations like the US Energy Information Agency (EIA) and the World Bank. (link)

In Energy efficiency and durability | Asked By Andrew Henry | Jan 12 12
1 Answer

I read the building science insight "Leiningen Versus The Ants Redux" by Joseph W. Lstiburek with great interest. I plan to build a workshop in upstate NY (zone 5+) using a similar approach. This seems very similar to the PERSIST method discussed in Martin Holladay's article "Getting Insulation Out of Your Walls and Ceilings".

But the details are tricky, as Joe learned with his barn. In Figure 1, Joe shows fully adhered membrane on top of the under-roof sheathing, on top of the roof insulation, and on top of the over-roof sheathing.

In Energy efficiency and durability | Asked By Clement B. Edgar III | Jan 13 12
2 Answers

We are building a cape in zone 6, Waldoboro Maine. I am considering the following wall assembly and have several questions regarding the components. Forgive the length of this, but I don't know how to make this any briefer.

In GBA Pro help | Asked By tom ruben | Jan 13 12
4 Answers

What is the effective strategy for increasing the R-value for an existing brick veneer wall over 1" airspace over 1/2" fiberboard sheathing(w/o WRB) over 2x4 studs with old not full depth fiberglass insulation between and plaster over gypsum lath finish? Given the generally excellent condition of the interior plaster I am unwilling to remove and re-insulate. Can a spray foam be used in the airspace injected from the exterior?

In Energy efficiency and durability | Asked By Peter Anderson | Jan 12 12
10 Answers

This is a clip from the following site;


The Real Problem of Subsidies

In Energy efficiency and durability | Asked By aj builder, Upstate NY Zone 6a | Jan 11 12
4 Answers

In a recently completed home of our design, the contractor - a firm I'd not worked with before - convinced the client to use spray foam insulation for walls and roof instead of the cellulose I'd planned. Part of his justification for accepting lower-than-code R-value of the roof was that the Delta-T of a sprayed roof deck assembly would be lower than if the insulation were at ceiling level. He noted that the air temperature of a vented attic would be some 30° higher than outdoor air.

In Energy efficiency and durability | Asked By James Morgan | Jan 13 12
6 Answers

Hi Martin,

Thank you for your article on radiant barriers. I hope you can help me. I
have a (hot in the summer, cold in the winter 2nd floor) approximately 1,300
(about 650 per floor) sq ft Cape Cod on Long Island, built in 1956 w/2 x 4 16" oc construction. I have already re-insulated w/R-13, vapor barrier fiberglass and added new drywall to the 1st floor. The 2nd floor has 2 bedrooms separated by the stairs in the center of the house. The 2nd floor
has an attic or crawl space, behind the knee walls, and though recently

In General questions | Asked By Jeffrey Kolsch | Oct 24 11
3 Answers

A builder I am doing energy consulting with has used tech shield roofing material on the exterior walls. The foil is manufacturer perforated for moisture. Is this a good or durable application for this sheathing? Will it effect the wall system?

In Green products and materials | Asked By Bruce Glanville | Jan 12 12
1 Answer

I've got some plugs in the siding now that indicates blown insulation was used. I don't know if cellulose or fiberglass was used, but my walls are COLD. I have already talked to my siding contractor about 4 inches of foam board and a layer of house wrap. Would it be overkill to add additional insulation inside the walls either on top of the existing insulation or by removing and replacing it? Spray foam insulation is all the rage right now, but the cost is substantially higher than cellulose or fiberglass.

In General questions | Asked By Jason Schaffer | Jan 13 12
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