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

Q & A Instructions

[Click map to enlarge]

The GBAGreenBuildingAdvisor.com web site has a wealth of articles on a wide variety of construction topics. Before posting your question, you may want to check out the articles on this page: How To Do Everything. You just might discover an article there that provides the information you seek.

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

If you want to post a question, 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!


1 Answer

Water Supply line routing

I'm building a house in Western Montana at 3500 ft, climate is not bad other than a couple week cold snap every year, though that may change. Had a couple of brain farts during the design in regards to water lines on exterior walls. It is a slab with radiant heat, so can't go in the floor.

The specs:
Shed roof, unvented with 4" ISO on the roof under rubber membrane.
Planning on R40 batts then drywall with very few holes other than some junction boxes for lights.

Walls are covered in 2" of ISO with 3/4 airspace behind siding.
Planning on batts or something in the R21 range.

Asked By Stan Smith | Sep 3 15
0 Answers

bring windows from outside the USA

I am building a new home in PA been looking for windows reached out to all the name brand window manufacturers in area , and canada I have a lot of windows, got quotes for 2 pan windows have run $45,000 - 65,000 3 pan windows quote have run $60,000- 70,000, was talking to my cousin who lives oversea easter Europe in cold part of country he just build a house with triple pan windows so I reached out the there local manufacture and there quote for UPVC windows rehau frames was under $20,000

Asked By boris rubinstein | Sep 3 15
11 Answers

I am considering getting solar panels on my roof

I am considering getting solar panels on my roof and have quotes from 2 different companies. Is there anywhere I can go to get help on determining which are the better panels?

Asked By Dave Sanda | Aug 31 15
3 Answers

Is this a risky wall assembly?

I am in the process of finalizing plans for a 2 story 2385 square foot home in Zone 6 WI 44.3353° N, 88.6389° W. I have been trying to get in the pretty goodish house category as far as insulation levels and while not where I'd like them to be am currently sitting with the following setup due to budget.

R10 EPS below slab insulation
R10 EPS exterior Foundation walls (will finish off basement later and can add interior insluation)
2x6 R20 damp spray cellulose with R7.5 Atlas Thermalstar LCI-SS EPS insulated sheathing
R55 blown cellulose attic insulation

Asked By Jeremy Coenen | Sep 3 15
5 Answers

Concerns about backdraft and make up air

We're in the process of air sealing a mid-Atlantic house built in the mid-80s. (Today is a humid 94 degrees and in the winter we go below freezing.) We had low CFM-rated (OKNA-brand) windows installed recently. After we seal the rim joists and the attic, I am concerned about what make up air and backdraft situation will be. We will be installing a 300 CFM range hood soon, too. Our water heater was just replaced with a power vented model, and we expect to replace the furnace very soon. We do have a wood burning fireplace.

Asked By Forum User | Sep 3 15
3 Answers

Vented attic vs. a sealed, non-vented, airtight attic

I'm building a new home in Miami, Fla.

An insulation contractor advises me to eliminate the planned roof & soffit vents and seal the attic with foam.
What are the Pros and Cons for maintaining attiic ventilation, and eliminating it?

Asked By Calvin Smith | Sep 1 15
6 Answers

Penetrations in exterior foam and rainscreen

I will be installing 3 or 4" of exterior foam with a 3/4" rainscreen and installing new windows and siding. This will be my first retrofit of this type.

Asked By Brian Otten | Sep 3 15
10 Answers

Is it OK to step the slab thickness over the footings to accommodate insulation between the slab and the footings?

I am building an addition on my home near Ottawa and I am adding two new sections of full-foundation on either side of the existing foundation, which has no under-slab insulation. I am adding 3 inches of insulation under the new slab, however for various reasons it is not practical to bring the 3 inches of insulation over top of the footings and right to the inside edge of the foundation wall.

Asked By Chris Seligy | Sep 2 15
11 Answers

How can I properly vent my tiny house roof (it has cross member framing instead of rafters)?

I have the framing almost complete on my tiny house, but I have run into a stumbling block. Framing the roof with cross members instead of traditional rafters made a lot of sense because the shorter span allowed smaller lumber for more head space and less weight, but upon further research my plan for venting is not going to work (I know - proper planning prevents poor performance). See attached picture for framing structure.

Asked By Ryan Reed | Sep 2 15
4 Answers

New 20+ SEER Variable Carrier heat pump w/ Greenspeed Intelligence system creating moisture & performance problems in the crawl

I had to replace 2 -13 SEER HVAC split systems in my house about 2 years ago do to some Sandy storm damage. One split system was a 90% gas furnace with a 3 ton 13 SEER AC and the other was a 2 ton 13 SEER heat pump.

Asked By Bruce Howe | Sep 2 15
Register for a free account and join the conversation


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