Q&A: A Forum for Green Building Experts and Beginners

[Click map to enlarge]

Please register for a free account or sign in to ask and answer green building questions.

The usual rules of courtesy apply:
1. Be nice.
2. If you can't be nice, be polite.
3. If you can't be nice or polite — well, please be brief.

To attach a photo or illustration:
Under the box labeled "More explanation," look for the words "File attachments."
Click that, and you should be able to attach a photo.

Thanks for joining the conversation!


10 Answers

Roxul Comfortboard - disadvantages?

I'm intending on insulating my 1950's Cape style house with exterior insulation. I've been planning on following the CCHRC's REMOTE wall assembly with an air tight membrane over the sheathing and 6" of EPS foam (2, 3" layers) then furring strips and siding.

Asked By Mark Fredericks | Oct 14 14
4 Answers

Basement ceiling insulation required by code — but what about the basement door and stairwell?

Seems like a huge thermal hole in the basement ceiling. Code requires R30 in zones 4 plus for unconditioned basements. What about the bottom of the stairs (to 2nd floor) and exposed stairwell walls? People typically just use an interior door to the basement, right?

Asked By Dwight Harris | Oct 15 14
3 Answers

Unusual thermal envelope intrusion at roof-penthouse

Hi,

I've discovered that the ~1987 penthouse addition to my house is partially outside the roof thermal envelope . Since it is attached (naturally) to the remainder of the house it compromises the performance of the whole house.

In a nutshell:

Asked By Keith H | Oct 14 14
27 Answers

My husband and I want to build an efficient house

My husband and I want to build an efficient house. The only problem is we are on a very tight budget.

Asked By K Nuss | Oct 11 14
10 Answers

Choose between more/better insulation, or heat pump?...

Last year we had an energy assessment performed in our 1880's home and were recommended several options. We opted to first pursue air sealing in attic with 20" of blown in cellulose. This made quite a difference both in comfort and heating bills.

Our remaining recommendations:

1 - Insulate walls with dense pack blown in cellulose.
2 - Insulate crawlspace (closed cell spray foam).
3 - Replace 4 windows original to house (drafty!!)
4 - Install high efficiency air source heat pump.

Asked By Christian Rodriguez | Oct 9 14
5 Answers

Closed-cell spray foam versus dense-packed cellulose - Noise control in a PassivHaus

This is a comment rather than a question.

In our pre-certified PassivHaus in northern NJ, we have 10-inches of densepack cellulose and 2-inches EPS in the walls, and 10-inches of closed-cell spray foam in the roof.

We've noticed that the noise attenuation through the walls is much greater than through the roof.

Most of the noise getting into the attic comes through the roof, which is asphalt shingle over plywood decking on 2x12 rafters, with the space between the rafters filled with 10-inches of the closed-cell spray foam.

Asked By Len Moskowitz | Oct 15 14
4 Answers

Sizing a minisplit for a 900-square-foot Chicago carriage house

I have a two-level carriage house (900 sq. ft. total). Brick structure, framed in with R-19 insulation, two levels, open loft style.

I'm wondering if the 12000 BTUH Mitsubishi MZ-FE12NA would be enough to heat the space, or should I go with the 18000 BTUH MZ-FE18NA?

Also, is there any reason why I should consider the Fujitsu minisplit too? I've had good experience with the Fujitsus in a warmer climate (than Chicago), but the specs on the Mitsubishi Hyper Heats seem hard to match in a Fujitsu.

Asked By timothy flynn | Oct 15 14
6 Answers

Insulating an attic furnace room

I have a furnace in my attic around which the builder constructed an enclosure from 2X4 and foil-backed fiberglass insulation. I've been told the R-value of the insulation should be sufficient, but there is clearly air getting through at the seams and creating hot spots in the attic which then leads to ice dams etc. What is proper protocol for insulating these attic "furnace rooms"?

Asked By Patrick Finn | Oct 15 14
3 Answers

Vapor barrier

So where do you apply the termite treatment when placing on com. site?

It only make sense to get your sub grade, apply your termite treatment, then your vapor, then your gab, then your steel/wire, then your concrete.

Anything else would put your vapor at risk of being damaged, right?

That's with 4 inch and 4 inch concrete.

Asked By mike brackett | Oct 15 14
1 Answer

Thoughts of REMOTE style building in eastern Canada

Dreaming of building a home aprox. 26x30 two story facing towards south with two large triple glaze casement windows (5'x5') per floor, my thoughts are to use REMOTE on a slab with 4" of exterior foam (eps) and blow in or roxul with in the stud cavities (2x6). The main reason, I am wishing to use REMOTE is for airtightness, plus the thoughts of having less wetting on the sheathing. Am I barking up the wrong tree? The home with be built in Charlottetown, PE.
I know this is very basic info, wishing to heat with minisplit.
Thanks Marty

Asked By marty nichol | Oct 15 14
Register for a free account and join the conversation


Get a free account and join the conversation!
Become a GBA PRO!