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6 Answers

Stone wool versus blown-in cellulose insulation in double wall assembly

I am designing a wall assembly for a home in a very cold climate Zone 7. Considering labor and material costs, what is the most cost effective insulation providing me with the highest thermal resistance? I like the fire resistance of Roxul stone wool batts and the idea that it's more DIY. How about the air transference between the two products? Thanks.

In Energy efficiency and durability | Asked By Matthew Michaud | Dec 30 12
1 Answer

Crawl space mold

1st off, where are my manners, thank you Martin for your answer regarding using damaged 4" roof mate for foundation walls. i did ask my building inspector about it as well...i was thrilled that he said yes and i didn't need to apply a fire-barrier like drywall to it. my guess is, because it's only 2' high and there is absolutely no storage in it.

In General questions | Asked By Nepal | Apr 24 17
6 Answers

March for Science

I'm sure that many GBA readers spent yesterday at their local March for Science protest. My wife and I, along with several friends, joined researchers, academics, middle-school science teachers, and lots ordinary people who care about the planet (and who use accepted means of separating truth from falsehood) at one of the hundreds of marches that happened all over the world yesterday.

Lots of good signs. Among my favorites: "I can't believe I'm marching for facts" and "Knowing Stuff is Good -- Seriously, why do I even have to march for this?"

In General questions | Asked By Martin Holladay | Apr 23 17
4 Answers

Can straw bales be used on the exterior of a shipping container home?

I am interested in building a shipping container home. Insulation is one of my biggest concerns. I have read a lot about the benefits of straw bales. I am very interested in using this as the exterior insulation, but have not found any info pro or con. Any help will be very beneficial.
Thanks for your info.

In Energy efficiency and durability | Asked By OrrinH | Apr 23 17
8 Answers

Roof membrane in ceiling?

In a commercial application we are putting a new floor over an existing roof that has an EPDM or TPO roof membrane on it. We feel this membrane should be removed for a variety of reasons, but, are getting questions from builders if it's necessary. If left, it would above a dropped ceiling, below the new floor deck. Is there a code addressing this or literature backing up it's removal? Thank you.

In Green products and materials | Asked By BryanD14 | Apr 24 17
8 Answers

Steel roof: to sheathe or not to sheathe?

I'm considering a steel roof for our new house build (hip design, 7 or 8:12 pitch) and I'm wondering whether sheeting first with OSB or plywood and a moisture barrier makes sense? I've done a little reading and it seems there are some who are in favor of sheeting and others who see it as a waste of time/money.

The main concern seems to be with moisture condensing under the roof when cool night air drops below the dewpoint of air in the attic. To this I question:

In General questions | Asked By Lance Peters | Apr 19 17
3 Answers

Air or vapor barrier for attic (using cellulose)?

Is there a certain air or vapor barrier that I should install before hanging ceiling sheetrock? The attic will be insulated with blow in cellulose. The attic will be vented at the soffit and with a ridge vent, nothing else. House is in zone 5. Probably R-40 to R-50 in terms of the amount of cellulose. I am looking at using the Certainteed smart membrane like I will on mineral wool walls.

In Green products and materials | Asked By Ralph S | Apr 24 17
11 Answers

2x4 rafters, skip sheathing, no insulation, help with roof choices

The shingled roof on my 1940 farmhouse in Zone 3b is due to be replaced. My wife and I are considering the virtues of metal for our very hot, very dry climate where electricity often exceeds $0.40/kw hr.

I plan to remove what little insulation is presently on the attic floor. The hvac ducts are also in the attic with little insulation and are likely poorly sealed.

In General questions | Asked By Edgar Pankey | Apr 20 17
3 Answers

Fiberglass-backed polyiso got wet, now moldy on surface: to keep or not to keep? Remediation?

A few months ago I chatted back an forth with Mr. Martin Holladay about my project... I have progressed on it since then, but have ran into an unforeseen problem. Let me bring you up to speed:

I am building an apartment underneath a lean-to roof coming off of a post-frame shop building in climate 3. I purchased some used poly-iso foam boards to use as insulation on the underside of the existing metal roof. At this time I have reached this point (Layers shown from top to bottom):

Metal roof
2x4 purlins (with subsequent 1.5" air gap)

In GBA Pro help | Asked By John Peeper | Apr 23 17
2 Answers

Double sheetrock + green glue + Membrane

I am going to be using mineral wool, a certainteed membrane, and possibly 2 layers of sheetrock (1/2" or 5/8") with green glue between them. Is there going to be any problem with this design in terms of the membrane's performance? I don't want moisture problems by using 2 layers of sheetrock + the green glue.

In General questions | Asked By Ralph S | Apr 24 17
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