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

Foamboard and creep deformation

I have been trying to find a way to insulate a brick ledge on the north side of my home. I am planning a large insulation upgrade to help get my floor heat somewhat working and seal up the house some.

In General questions | Asked By Michael McArdle | May 11 15
3 Answers

Insulating rafter bays with sistered roof rafters

I have a newly constructed home in Massachusetts, built to minimum energy standards (or maybe a little below).

The attic is unfinished, but the builder planned to finish it one day so he insulated the 2x10 rafters with a "flash & batt" approach. There are 4 inches of a sprayed on foam in the rafter bays (I would guess R-24 to R-28) and 3.5 inches of R-15 fiberglass. The fiberglass is held in place with vinyl straps and a layer of Membrain vapor barrier. There are soffit vents and a ridge vent, but these appear to be unused and blocked by the foam, at least in the rafter bays.

In Energy efficiency and durability | Asked By David Lewinnek | May 14 15
21 Answers

Air Scrubber Plus

I am considering installing an Air Scrubber Plus system on Zone 1 for my house. I have a coworker who has installed one and says it has worked great for treating indoor air (particularly cooking smells). I was curious if this system is worth the money? Is it worth it given the lifecycle cost - replacement of the bulb (almost as much as the system)?

Just looking for anyone who knows more about UV bulb filtration, the risk vs. reward, and in particular about this manufacturer and their product.

The link to the air scrubber plus is here: www.airscrubberplus.com

Thank you!

In Mechanicals | Asked By Shaun Kennedy | Sep 11 14
1 Answer

Wall system for recording studio / home. Vapor questions?

Hello, thanks in advance for your time and knowledge. This site is a great resource.

I am building a home / recording studio in Murfreesboro, TN (zone 4A) and have some questions about my wall system. My plan is to build my walls in the studio as such: vinyl lap siding, 1" xps foam taped at all seams, osb taped at seams, 2x4 walls with rock wool batts, 5/8 drywall, 1/2" sound stop fiberboard and finally one more layer of 5/8 drywall painted. All air sealed as best I can. My question / concern is about vapor.

Does this wall system pose any issues with vapor?

In General questions | Asked By JOE ROBERTS | May 13 15
6 Answers

Flat roof advice needed

I’m building a carport and breezeway in southeastern Michigan and I’m struggling with construction methodology and products for the proposed flat roof.

Flat roof? I know…Martin's Ten Rules…But… I would like to use all this roof real estate. This roof will cover a substantial portion of my small urban lot and I think, in the future, this could be valuable space. A Small Deck, a Modular Green Roof, Potted Gardens, Solar Panels…

In General questions | Asked By Howard Road | May 11 15
3 Answers

Spraying foam into stud bays without any kind of barrier

One of my clients has a pre-war home, (Civil War, that is), and would like to spray foam into the stud bays, although there is no barrier of any kind. Just old pine siding nailed to the studs.
I told him first that he should re-naill the siding using splitless ring shank nails to secure the siding.
Without any kind of barrier, I envision foam squirting out between the gaps.
Short of removing all the siding, and installing a vapor barrier, I suggested lining the stud bays from the inside using roofing felt stapled to the studs encapsulating the stud bays.
Any better ideas?

In General questions | Asked By roger steinbrink | May 13 15
2 Answers

Moisture protection in the crawl space

Does the moisture protection in the crawl space ever need replacing. The one under my house is 12 years old and I was told that moisture protection covers need replacing at least every seven years. Is this true or is it a ploy for business?

In General questions | Asked By Janet Swope | May 13 15
1 Answer

Passive solar orientation and shade-free zone

Friends,

I am writing to double-check my thinking on our passive solar building orientation and a shade free zone.

Next week a surveyor will stake out the building layout for our 1,100 sq foot passive solar home at 46 degrees N in Minnesota.

The structure's southerly, solar-gain wall will be oriented at 210 degrees (30 degrees W of true south). Solar studies I have done show that we will get good sun light penetration into the structure during the winter with this orientation.

In Energy efficiency and durability | Asked By Randy Bunney | May 13 15
1 Answer

Are Europly, Appleply or good Baltic Birch plywood available in Vermont?

I am specifying materials for millwork and want to use a good baltic birch plywood so I can expose the edges (rather than edgebanding). What is available and a good/not too pricy choice in Vermont?

In Green products and materials | Asked By Anke Tremback | May 13 15
2 Answers

XPS & global warming: Updates?

I keep reading that different, less harmful blowing agents than HFC-134a were supposed to come online for XPS foam. Some of these articles date back a few years, and make it sound like the change was imminent. Did any of this ever come to pass? Or are we still dealing with the status quo? The latest article of this kind was on GBA a few months ago. http://www.greenbuildingadvisor.com/blogs/dept/green-building-news/new-b...

In Green products and materials | Asked By Peter Rogers | May 12 15
Register for a free account and join the conversation


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