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10 Answers

Do I have to clean out and replace the Great Stuff?

I have been back-side and edge sealing and also sealing the gaps on the inside of electrical boxes with Great Stuff Door and Window (low expansion foam). Then today I saw a blog that says Dow advises not to contact it with copper wire. I called them and they said its flammable during installation and when cured.

Do I have to clean out the Great Stuff and switch to another product for air sealing electrical boxes? If so, any suggestions.

Thanks in advance

In General questions | Asked By Oak Orchard | Feb 15 13
8 Answers

Insulating a strapped attic floor

Need to insulate an attic floor with 24oc/12in high truss joists that have been strapped with 1x3 strapping, 16 oc across the underneath of the joists. 1/2 blue board is attached under the strapping and veneer plaster makes up the ceiling. 2 coats of Behr ceiling paint is on the plaster.

In Energy efficiency and durability | Asked By stephen edge | Feb 19 13
2 Answers

Insulating a void in basement.


I was wondering if the experts here could help me with an insulation question.

I have a fireplace in the basement that we do not ever use. It is a slight bumpout from the house. There is a bathroom just above it on the first floor (the chimney angles up to the left and does not interfere with the bathroom). As a result, there is a void above and behind the fireplace and below the 1st floor bathroom (roughly 40 inches to the foundation wall).

In Energy efficiency and durability | Asked By Allan Wood | Feb 18 13
5 Answers

What type of insulation and how much insulation should I use between ceiling joists in garage?

I live in zone 5 in northern New Mexico and live in an apartment above a 3 bay garage. The ceiling joists in the garage are 2x12 on 12" c/c. The only heat source for the upstairs is from a small wood stove. I need to insulate the ceiling of the garage below. The garage walls have no insulation. What type of insulation and how much insulation should I use between ceiling joists in garage? Also I would need to insulate the rim joists.

In Energy efficiency and durability | Asked By James DeCastro | Feb 19 13
1 Answer

Insulating using the 1/3 2/3 rule in zone 7

I would like to get some opinions on the 1/3 2/3 rule for applying insulation in walls in Quebec, Canada. Could one get by applying the rules for insulating the sheathing noted in the GBA article "Calculating the minimum thickness of rigid foam sheathing" (http://www.greenbuildingadvisor.com/blogs/dept/musings/calculating-minim...)? For our region we would need to add R-15.

In Energy efficiency and durability | Asked By jessie pratt | Feb 19 13
6 Answers

Green roofs: what's the verdict?

I'm intrigued by the idea but see several obvious problems: 1) leaks, 2) expense, 3) maintenance (weeding etc.), as well as a less tangible but possibly significant issue: 4) prospective home buyers viewing a green roof as a liability (we plan to be in the house for a long time, but plans can change.)

In General questions | Asked By Ray Sten | Feb 14 13
1 Answer

To rainscreen or not to rainscreen?

Hello GBAers,

I'm building a small (250 sq. ft.) cottage in my backyard in the Bay Area in California in climate zone 3C. We plan on using stucco for the exterior as it will match the main house.

The cottage will have one-foot overhangs because it's near the property line. Code around here is two layers of Grade D building paper under the stucco, but I know a lot of you guys believe it's better to add a rainscreen between the paper and the stucco.

In my research, it seems that a lot of the rain screen products are insanely expensive.

In General questions | Asked By Nick Jensen | Feb 19 13
5 Answers

HRV duct penetration

I've got a bit of a condensation problem with a cold-air duct. It's
the fresh-air intake for the HRV, made from a big PVC pipe [for less
thermal bridging than metal] run through a wall and air-sealed
around where it passes through the inner and outer wall layers.
It connects to a piece of insulated flex-duct that runs to the HRV,
with the fiberglass blanket and outer cladding of the flex pushed
right up against the inner surface of the wall to try and expose
none of the cold parts to the inside.

The fiberglass is at the heart of the problem: interior air appears

In Green building techniques | Asked By Hobbit _ | Feb 15 13
5 Answers

Reverse air conditioning?

We live near the Pacific Ocean, where the climate is cool (average about 60-65) year-round. In locations where the sunlight is unfiltered, the light can be quite intense and create a lot of heat. So on a normal day, our attic can be extremely hot--over 100--while the house remains very chilly. Because we have good insulation in the attic, that heat does not come into the house.

It seems to me that there should be a way to pull that daytime attic heat (the attic is very clean) down into the house, but I have not been able to find out how to do that.

Any ideas?

In Energy efficiency and durability | Asked By Maureen Girard | Feb 14 13
9 Answers

When insulating attic rafters, should they be completely filled or should there be room left for air movement?

Attic is finished room, had water damage from use dams, old insulation did not fill rafter completely

In Green building techniques | Asked By Paul Elvord | Feb 16 13
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