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!


2 Answers

Continuous Running Bath Fans

We've noticed a black film on the vinyl siding around the exhaust vent of the continuous running bath fan on several houses we have built. It seems like the exhaust could be facilitating mold growth, or just causing the siding to be dirty. Has anyone else come across this? Does this mean the bath fan is just doing its job and cleaning the siding around the exhaust would be normal maintenace? Thanks

In Energy efficiency and durability | Asked By Jason Hackworth | Aug 10 12
1 Answer

Do I need an interior vapor retarder if the studs are filled with spray foam?

For a new wood-framed single-family home that has spray foam insulation installed in wall, is an additional vapor retarder required to be installed on the interior side of wood studs?

The code does not address as far as i can see.

In Building Code Questions | Asked By william griswold | Aug 10 12
5 Answers

Would this work?

In Energy efficiency and durability | Asked By Rocky Pembroke | Aug 8 12
5 Answers

Insulation of a flat roof

I am considering having my flat roof insulated using blown in fiberglass insulation. One contractor I've consulted accesses the space by cutting holes through the roof deck and then installing roof vents to cover the holes once the fiberglass is installed. My building is approx. 25' x 60". The contractor recommends the addition of 2 roof vents. Currently, my roof is not vented and because the building is approx. 90 years old, I am assuming that there is no insulation in the space between the roof deck and the interior ceiling.

In GBA Pro help | Asked By Susan Lane | Jul 20 12
1 Answer

Need to feature a Net Zero Electric Home in Forest Environment?

Hi,

I would be happy to share my almost net zero electric home surrounded by 50-100 foot tall pine trees. Let me know if you are interested in an article, tour, ect.

You can see a planned tour and info. of my home by going to Going Green GeoTourism.

I can be reached at 530-386-5678

Sincerely, Scott Terrell

In General questions | Asked By Scott Terrell | Aug 8 12
4 Answers

Acoustic sealant for sealing between plywood subfloor and wall bottom plate

For our home construction project we need to decide what sealant to use between the subfloor and the bottom plate. Our builder commonly uses Tremco Acoustical Sealant for this purpose. While I gather from the information in this community and generally on the web that this product is mentioned and used very often, the reservation I have is its very high VOC content.

In Green products and materials | Asked By Manfred Winter | Jul 31 12
3 Answers

Radiant Barrier Warming House?

I installed a foil bubble double sided radiant barrier over the attic rafters in my townhouse. I didn't measure temperature in the attic prior to installing, however, since the radiant barrier was installed it seems to get very hot in the attic during the day, and that heat seems to be keeping the house warmer.

In GBA Pro help | Asked By Rocky Pembroke | Aug 8 12
5 Answers

Air sealing or Insulating firebrick

In our new-to-us 1940s dormered cape just outside of Boston, we have some firebrick just above the sills. Looks like it's stuffed in between the balloon framing to stop fires from going into the upper levels.

When we bought it three months ago, it had dirty glass batts between the joists covering the bricks. I've since ripped them out and I'm looking for options. Hope there are some that will let me inspect for termites and moisture later.

In General questions | Asked By stephen edge | Aug 8 12
1 Answer

What is "plenty of soffit vents"?

I think I understand "Lstiburek’s Rules for Venting Roofs". I need to contract for insulation and a new roof on a property (1950's duplex) in the Pacific Northwest. The building has soffit vents - about 3 (approx 18” X 6”) per side, so 12 vents and NO other vents up top (has been like that for years and no moisture problems in the attic which does have insulation). Should I make the soffit vents continuous? Or, since it has been working well for all these years maybe just add a few more soffit vents and a ridge vent at the top (not to exceed in size the area of the soffit vents)?

In GBA Pro help | Asked By Marsha Henry | Aug 8 12
2 Answers

Is a foil-faced OSB roof deck worth it?

My framer suggested we use foil-faced OSB for the roof deck, which we did. But, knowing that a reflective surface is effective mostly when there is an air space next to it, I was wondering if foil-faced OSB is worth it. When used for roof decking the foil facing would be to the inside of the attic and it would seem that it would be ineffective in reflecting heat away from the house.

In Energy efficiency and durability | Asked By Robert Sanders Jr | Aug 8 12
Register for a free account and join the conversation


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