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!

11 Answers

My designer and I are designing a house as close to passivhaus standards as we can get. We have agreed to design it with SIPs but he thinks a truss roof with spray insulation would work just as well. I'm thinking a SIP roof eliminates potential for thermal bridging and is less costly to install versus the truss roof.

In Green building techniques | Asked By scott schroeder | Aug 29 14
5 Answers

Most of the blower door tests that are mentioned on GBA give numbers under 3 or 2 or 1 ACH50. I'm guessing that none of these homes have a traditional fireplace. How much does a traditional fireplace with standard chimney damper contribute to air exchange numbers? What are some recommendations for improving a house with fireplace and chimney?

In Energy efficiency and durability | Asked By Derek Roff | Sep 1 14
5 Answers

I am replacing my existing siding and I am doing the following -stud - 5/8" plywood - 1-1/2" of Polyisol, 3/8", WRB, rain screen, fiber cement siding. The house is in the San Francisco bay area on a hill with a stepped foundation.

In Energy efficiency and durability | Asked By Randy Mason | Aug 30 14
3 Answers

Wondering if the arctic wall design would be appropriate to use as a roof/cathedral ceiling here in CZ6 upstate NY. There is a comment about it on Martin's blog, but I didn't see any discussion : http://www.greenbuildingadvisor.com/blogs/dept/musings/how-build-insulat...

from inside out it would be:
GWB,
2x4 service cavity,
1/2" CDX taped and sealed,
parallel chord trusses 12-12 pitch dense packed with cellulose,
vapor open WRB (suggestions for best product welcome),
2x4 furring,
5/8 sheathing,
felt,
asphalt shingles.

In Green building techniques | Asked By Trevor Chadwick | Sep 1 14
4 Answers

I have a question about an effective way to solve an issue in a house with a large family room that has a painted T&G wood planked vaulted ceiling that leaks air and makes the house very cold in the winter.

In Green building techniques | Asked By Bruce Howe | Sep 1 14
1 Answer

Hi,

I am in the middle of a bathroom remodel. My house was built in the late 60s and is located in climate zone 6 (Quebec). My question is about the damaged kraft paper that is supposed to act as a vapor barrier. From what I can see the wall assembly is (from the interior):

- Drywall
- Kraft paper
- Furring strips
- Some cardboard fiber and studs
- Probably batts insulation (I can't see behind the cardboard)
- Tar paper and exterior sheeting (brick)

In General questions | Asked By Guillaume Dumont | Sep 1 14
1 Answer

I am finishing the exterior basement walls in my new home. My plan is adhere rigid to the foundation walls, after that I'll be putting down dricore subfloor, then studding up 2X4 walls on top of the dricore. There will be an air gap between the rigid and the 2X4's as I am laying in R-20 "2X6" batts. Plastic vapor barrier will complete the system before the drywall.

In Green building techniques | Asked By Mark McKenzie | Sep 1 14
19 Answers

I would like to decide on putting in solar panels to reduce energy costs.

I have read about the next generation solar panels not being to far off.

Question: Would it be better to install current solar panels or wait for the new type that will be coming shortly?

In Green products and materials | Asked By John Alberti | Aug 26 14
16 Answers

This is something that as passed a few times in my background brain processes,

How does SHG on exterior cladding/glass influence heatloss ??

If glazings specs 50%VT , a part of the remaining 50% must be converted to heat?

If exterior cladding on a building is black, and sun is shinning on the south face,
it must affect the heatloss greatly for the shined on walls ??

As an example, let's assume a building up here cold north.
20c inside 0c outside.
Sun shines on a large flat south wall that was cladded with a black painted steel sheets finish.

In General questions | Asked By Jin Kazama | Aug 28 14
42 Answers

I had R60 blown into my 1000sqft attic where there was previously only about R11. Baffles were installed in almost every roof rafter. Air sealing of attic floor was performed. This is a low pitch asphalt shingled hip roof over the whole house.

In General questions | Asked By Jeff Watson | Jul 12 14
Register for a free account and join the conversation


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