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

Windows for my Pretty Good House

Hi all

Another question for the experts here at GBA--this time about what windows I should install in my Pretty Good House (PGA). I've written here before about this house and you can likely find the threads of previous questions. Basically, we're building a single level, 1700 sf house in Hood River, OR and we're trying to meet PGA and passive solar "standards". Currently, we're trying to decide what windows to put in this house, and the candidates are:

Marvin Integrity
Milgard Ultra
Intus Arcarde or Eforte

Asked By Matt Mesa | Sep 29 14
5 Answers

Hot water re-circ line & vertical head loss

Hi all,

I’m trying to size a pump for our re-circ line. We have a 1 story house, with a tankless water heater in our attic at one end of the house. Our 2 bathrooms are at the other end of the house.

Asked By Joe G | Sep 30 14
4 Answers

LED GU24 base bulbs

I plan to buy new lighting with GU24 2-pin sockets for my kitchen renovation. But I'm noticing many more choices of LED lights with the regular twist on base now. Will the LED GU24 base bulbs continue to have a poor pool of choices while the LED twist on consumer choices will grow? Basically I will always use LED, but I want to have the option of "nice looking" bulbs too.

Asked By Kelly Proctor | Oct 1 14
12 Answers

Please tell me why I have to put so much insulation / outsulation at the roof/celing?

This may be a stupid question.......... but, I am building a pretty passiv/aggresive house in Zone 3 and my mandated (code) R-values are as follows:

Ceiling R-value 30
Wood Frame Wall R-value 13
Mass Wall R-value i 5/8
Floor R-value 19
Basement Wall R-value c 5/13f
Slab R-value d, Depth 0
Crawlspace Wall R-value c 5/13
Fenestration U-Factor b 0.50j
Skylight U-Factor b 0.65
Glazed fenestration SHGC b, e 0.30

Asked By leo kloop | Sep 30 14
20 Answers

How do you insulate cob or earth bag walls in the Northeast?

Hello everyone, I am brand new to this forum even though I have been spending the last three months here reading and enjoying the comments and articles.

My wife and I are looking to build a cob house / cottage. We live in western NY where winters are snowy and there is substantial moisture. After some extensive research we do not feel completely comfortable with straw bale and are leaning towards building with Cob for all the obvious reasons. 1. it will be cheap. 2. We have lots of clay. 3. It will last, no termites, fire resistant and we can be more creative etc...

Asked By Aaron B | Sep 27 14
4 Answers

Zone 5 - Cathedral Ceiling

Hello all. Long time lurker building a new house by Candlewood Lake in CT. We are currently finishing up framing and I am getting all kinds of debate on the cathedral ceiling in my master bedroom. Above it is proposed 2 x 12 rafters and we were going to go with a vented dense packed cellulose insulation. Now I am considering adding a 1.5" layer of PolyIso on the inside.

Is there any potential to not vent? All the articles I see here strongly suggest venting when dense packed cellulose is used in a cathedral. What say you?

Is the 1.5" of Polyiso worth it?

Asked By Paul Szymanski | Sep 30 14
5 Answers

I'm getting two different opinions about foam insulation in the attic

Some say spray the roof deck-allowing the attic air to become conditioned which is great for the H&A ducts in the attic. Others say spray the attic side or the ceiling to allow the attic to vent. I don't understand this one since the attic air is now unconditioned air and the ducts a
have only a wrap of insulation..I'm confused. Sounds like there are two schools of thought going on. Are both ways OK? Is one a lot better than the other? Help!! I even heard that the house would be too tight and allow for stale air to remain in the house if you spray the roof deck..I need answers.

Asked By Rus Pearson | Sep 30 14
6 Answers

Cupping shingles on brand new roof?

Hi everyone,

Asked By Tony Johnson | Sep 27 14
12 Answers

Grid-tied without independence … what’s the point?

Grid-tied without independence … what !?! … what’s the point …

Just read this at RMI and was shocked at the prospect that grid-tied PV systems (and probably wind, too) are not normally run by servo mechanism that locks out the network to favor independence in the event of a grid failure. That’s just dumb.

“When The Power's Out, Solar Panels May Not Keep The Lights On”
http://www.npr.org/2014/09/17/348987688/when-the-powers-out-solar-panels...

Asked By flitch plate | Sep 29 14
8 Answers

Is continuous polyiso over plywood and concrete wall OK?

I have a 200-year-old timber-frame Cape in western Massachusetts. Last year we had Mass Save insulate the roof and three side walls with dense-packed cellulose. Unfortunately the fourth wall was an addition (70's or 80's) and already had fiberglass so the program couldn't do anything to improve it.

We are ready to tackle this final wall. Since the inside is finished we won't be removing the fiberglass but will be adding rigid foam to the outside.

From outside in our details will be:

  • 1 x 10 Ship Lap Siding (Vertical)
Asked By Jamie Malcolm-Brown | Sep 30 14
Register for a free account and join the conversation


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