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4 Answers

Mitsubishi heat pump defrost mode

I just had a Mitsubishi MXZ-4C36NAHZ with a 24kbtu and 9 kbtu unit installed in my house in Vermont. When the temp drops below freezing, my indoor units blow cold air (as in really cold. Not just a fan circulating air, but COLD). This is a quote from the brochure: "and because the system fan turns on only after the target temperature is reached, it NEVER BLOWS COLD AIR."

1. First if that's true, what's happening?

In Green products and materials | Asked By Joey | Dec 22 15
4 Answers

Wanting to install new casement windows

The house is full brick veneer ranch 1955 north/south orientation zone 5a. I have blown cellulose in the wall cavities. Cellulose is going to be added to attic after the rewire. Having a hard time choosing the casement windows for this house. It has the original Pella roll screen windows. Which I think were installed prior to the brick. There is 2" from rough opening to the brick. I am thinking I will add the brick mould after the windows are replaced. All white in color is fine with triple panes. What would be the most bang for the buck?

In Green products and materials | Asked By Greg | Dec 23 15
10 Answers

Unfinished third floor insulation

I have a fairly new house (2004) and I am convinced something is wrong with it. Located in NH, it's a basic square colonial with a full shed dormer rear in the attic, and a normal sloped (cape style) flat roof in front (no dormers at all).

In GBA Pro help | Asked By Jeff | Dec 15 15
16 Answers

Does anyone have thoughts on this wall section in regard to avoiding moisture problems and drying to the interior & exterior?

I am an architect in Boston preparing to build a home for my family on a marshfront site in Scituate MA (Zone 5 and 110MPH winds due to coastal proximity). Energy conservation is a key goal for the project. Originally I was planning an R48 double stud wall but circumstances have changed and I am now planning a single 2x6 stud wall with cellulose cavity insulation and rigid exterior insulation - total wall R value is about R38. The thinking on vapor / air / moisture barriers and retarders has gotten so complicated in recent years.

In GBA Pro help | Asked By sean stewart | Dec 20 15
1 Answer

Flash and batt on a sloped roof

The spray foam crew started work on my house today. One of areas getting CC spray foam is the sloped portion of the roof on the room over the garage. For the sloped portion of the roof, there is roof sheathing, a ventilation baffle, spray foam, and the rest of the cavity will be filled with fiberglass batts.

In General questions | Asked By Michael | Dec 22 15
3 Answers

Plumbing penetrations in a basement

I have a few plumbing holes between basement and 1st floor -- all are tight to the wood floor, no big holes under the bathtub or big gaps next to the pipes or anything.

If these plumbing pipes definitely go only to the 1st floor and are under toilets etc, should I still air seal with spray foam? Assume the answer is 'it can't hurt' but I'd be surprised looking at them if they are major sources of air leaks.

My other plumbing holes that run to 2nd floor are already air-sealed with spray foam in the attic. Should I air-seal them in the basement too?

In Energy efficiency and durability | Asked By Justin | Dec 22 15
8 Answers

Can rigid foam be used for unvented attics on the inside?

I have a fairly old (100+) house with unvented eaves, and I am doing some work on the top floor, which used to be the attic, but was mostly finished into livable space about 50 years ago. We have a very steep roof, with standing headroom even above the finished attic space.

I have gotten some recommendations from insulating contractors which include 5.5 inches of spray foam (very costly), and in one case an inch of foam between rafters followed by dense-pack cellulose. The rafters are 2x6, and the roof has planks instead of sheathing.

In General questions | Asked By Rowan Atalla | Dec 22 15
2 Answers

A-Frame insulating

I just bought a 76' A-Frame that has 2x6 roof/wall supports. I have it gutted down to the studs right now. I am having the hardest time trying to find out how to properly insulate an A-Frame! I am not into using the spray foam technology. I live in the mountain of SW Montana so it's cold in the winter. I was thinking about using 2 layers of ridged 2" foam board. Leaving a 1.5" space between the roof sheathing and the insulation. The insulation would be flush with the roof/wall 2x6's. Then a vapor barrier over all that. Tongue and groove pine over that then.

In Energy efficiency and durability | Asked By Korey Kaz | Dec 22 15
2 Answers

New home in Delaware on the bay.

Planing cantilever decks 2nd and 3rd story. Four foot width both sides mainly for maintenance as I want to stay off ladders as I get older. Should I insulate the interior bays where cantilever joists enter interior. Cantilever decks as cost savings instead of wood pilings along both sides of home.

Thanks much for your help

Happy Holidays

Ed Serafin

In Energy efficiency and durability | Asked By Edward Serafin | Dec 20 15
3 Answers

Question about building envelope/insulation around garage and walls bordering garage

As you may recall, we put 2 layers of foam (7" XPS and 2.5" EPS) above our 1:12 roofline so the attic is conditioned space. The exterior of our house will have 2" rigid foam and EIFS. Exterior 2x6 wall cavities will be filled with blown-in cellulose.

In Green building techniques | Asked By Kevin Hoene | Dec 21 15
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