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5 Answers

Blower door questions

We are about to perform a blower door test on our small 650 sq. ft. new construction house. I have four quick questions:

1. We used T&G OSB and Siga tape for our air barrier, and i think we did an extremely thorough job detailing it. the house is not quite complete, however. for example, the clothes dryer is not installed, some of the joints in the hrv ducting in the crawlspace have not been sealed, the drywalled window returns have not been latexed to the window frames, etc... will these items have a significant effect on the test results?

In General questions | Asked By erik olofsson | May 23 13
23 Answers

Cold sheathing question

Martin, I read your article on cold sheathing. I'm still not clear on one point: how do you know if the sheathing is wet due to the sheathing being cold and taking on moisture or the sheathing being wet due to vapour making its way from the interior of the house?

In General questions | Asked By erik olofsson | May 22 13
7 Answers

On average in New Mexico what is the cost per square foot to build a completely green home with the best insulation?

On average in New Mexico what is the cost per square foot to build a completely green home with the best insulation? It should be a passive solar home.

I need this information for insurance purposes in case I am in need of total reconstruction due to complete loss of our current home.

In General questions | Asked By Leah Popp | May 22 13
2 Answers

Underlayment to use with hardwood


Wondering what the opinion is on an underlayment for a hardwood floor.
From what i understand the main reason for an underlayment would be to have Vapor retarder (not barrier!) to slow the water vapor (if any) from passing thru the hardwood to fast which could possobly cause cupping and other issuies. Please add or correct if i am wrong.

slab > 6mil poly > 1" polyiso rigid foam > 5/8 advantec.

I think the advantec has a perm rating of 1-2

In General questions | Asked By mark kessler | May 22 13
4 Answers

A-Frame re-roof - what type of (if any) air barrier?

I have an A-Frame (steep pitch cathedral roof) built in 1975. It is an unvented roof. Region 5, southern NH. It needs new shingles. The existing roof from inside out is:
5" x 14" laminated rafters 14’ OC
2-1/2" thick T&G decking
2" rigid insulation
Asphalt shingles nailed through insulation to deck

Removing the old shingles will harm the existing insulation, and I can find no existing air barrier. The roof is leaking.

The proposal under consideration is:
Remove existing shingles and insulation
Install air barrier to deck

In General questions | Asked By BIll Berzins | May 22 13
1 Answer

Does it make sense to choose glass that is slightly less insulative but has a higher SHGC and VT?

I live in a heating-dominated climate with many cloudy days. Taking all window buying considerations into play I have found the replacement window decision-making process tricky.

I seem to have found a pretty good window sold through the local lumber yard here in Missoula, MT. It is a Plygem vinyl triple-pane marketed as R-5 glass. The marketing is slick but the real values as rated by the NFRC back it up. Or seem to. Does anyone have feedback about this Plygem product?

In Energy efficiency and durability | Asked By martin fahrney | May 23 13
6 Answers

Insulation method

I am building a new home and looking for the best way to insulate. I think the spray foam is the best but also the most expensive.

My builder is researching a new foundation water proof system called Enviro-Dri. Does anyone have any experience with that, or do you have another method you like better?


In Energy efficiency and durability | Asked By lisa lockwood | May 20 13
2 Answers

Tax credits or incentives - Federal or state?

Hi, getting ready to build and it seams like there ought to be some substantial tax credits or incentives for building a super insulated and energy efficient home...can't find any though...am I looking in the wrong places or are there really no incentives for new construction being done right? Location: Idaho.


In General questions | Asked By Eric Mikkelsen | May 21 13
4 Answers

Does anyone have experience with the Dow Powerhouse Solar Shingle?

Can the Dow Powerhouse Solar Shingle be safely installed on an unvented cathedral ceiling/roof which is insulated below the deck with impermeable closed cell insulation. will this Dow system trap moisture and condensation below it? What about the Certainteed Solar system which is installed directly on the roofing deck? For solar PV systems with modules raised off the roofing deck, what is the long term effect of shading, moisture and fungus on these shingles? Do these shingles below the raised solar PV module have to be replaced before the life expectancy of the solar PV system?

In Green products and materials | Asked By JOSEPH POLAND | May 19 13
4 Answers

Does earth coupling work?

I've purchased a city lot in Tucson, AZ and plan to build a tight, well insulated home on a concrete slab-on-grade within the next few years. It's a hot, dry climate with 1578 HDD, 3017 CDD, so obviously keeping the house cool is the big concern.

In Energy efficiency and durability | Asked By Michael McNulty | May 20 13
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