Community: GBA Pro help

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!


9 Answers

Attic insulation question

I have read many of the posts and articles about different ways to bring an unconditioned attic into the thermal envelope of one's home and I'm currently weighing some options. I will likely use spray foam under the rafters of my attic (9.5 inches). I've read the various debates about using less spray foam than would be required to achieve the desired R-value (eg R of 49 in my zone 4a area), with the argument (from the spray foam manufacturers it seems) being that spray foam yields a more effective R-value so you don't need as much as you would think based solely on R-value calculations.

Asked By Rob Moore | Jun 17 16
10 Answers

How can I stop the mold recurring in my wall?

I have a bonus room over my garage with a double window at the gable end. The outside of the wall is brick faced, wrapped in Tyvek over OSB. The inside has fiberglass insulation, and drywall. The house is 12 years old, located in the Midwest.

Asked By Carr Bruton | Jun 18 16
16 Answers

How do I vent this floor sleeper assembly? Or do I need to? Help!

Redo of old commercial alley space.. 2 story brick bldg turned into sfd

Floor assembly:
1. built on existing slab on grade that is about 1" above grade in an alley
2. existing slab had some cracks in it and some plumbing with short plumbing trenches in it. 6/23/15
3. 6 mil poly layer
4. 2x6 pt sleepers joists at 16" oc solid blocked about 4' oc 6/25/15
5. 3" closed cell foam sprayed in joist bays 6/30/15
6. 3/4" t&g osb floor sheathing 1st week of July/15
7. 5" wide 3/4 solid red oak flooring on flooring paper. 8/12/15
8. Client comment about cupping 10/15 or 11/15

Asked By Carey Hoobler | Jun 6 16
13 Answers

SEER, COP and HSPF

I am trying to come to grips with SEER, COP and HSPF.

Is this correct:
SEER is BTU cooling / watt hours needed. So divide this number by 3.412 to get the COP. Thus a 16 seer unit would have a COP of 4.7 or so.

HSPF is BTU heat produced / watt hours needed. So take a heat pump with a HSPF of 10, which is supposed to be pretty good and divide that by 3.412 = a COP of 2.9.

Have I done that correctly and, if so, are there heat pumps that do better than a 10 out there?

Asked By Amanda Evans | Sep 10 09
6 Answers

How do I prevent ice dams in this area in the future?

House is in North Central NJ, zone 4a, 2x4 construction, built 2005-6, ~4500 sq ft, insulated with batt insulation, unfinished and unconditioned attic with gable, ridge, and soffit vents. We are not the original owners so didn’t have a say in the design or build specs but there are clearly lots of elements that run counter to many of the views espoused here e.g. complicated roof design, 2nd floor heating/cooling unit and duct work in attic, house not air sealed or as insulated as it could be for a modern home, etc. That said, we like the house and area and plan to make some improvements.

Asked By Rob Moore | Jun 5 16
14 Answers

Attic insulation quandary

Seeking advice on renovation plans for a 1910 house in ND - Zone 7.

HOUSE DETAILS:
- 2 1/2 stories above ground with full basement.
- 2nd story has 'sun porch' facing south.
- 2 layers of siding. Inner layer has lead paint (of course)
- Insulated in the 70's with formaldehyde foam, holes drilled through exterior to fill cavities.
- High efficiency propane furnace, forced air.
- 2 chimneys.
- 1st in middle of house used for original oil-burner furnace and water heater. Now used by wood fireplace in basement.

Asked By Tim Lange | May 16 16
12 Answers

Is it possible to repair a SIP roof that is rotting?

We built an SIP home using panels from ACH Foam Technologies. The roof was installed according to manufacturers specks. The panels were OSB on both sides of expanded polystyrene insulation, about 7" thick. Block splines were installed with the prescribed Do All Ply sealant. This design had space between the lines of calk for air to move vertically. The OSB has begun to de-laminate at the seams visibly under the shingles.

Asked By Allan Poole | Sep 6 15
10 Answers

Stamped concrete patio near foundation

Hi all,

I have a couple of questions regarding a patio near the foundation of our house. My wife and I have been dealing with water issues in our basement/crawl space for a while now, and we just recently had a contractor in to seal the vent properly, install a membrane along the foundation wall, and add French drains tied into the downspout.

As the last part of this work, we have removed a surface deck that the old owners installed and are looking to install a stamped concrete patio with the same dimensions (14x30) pitched away from the home. Specifically my questions are:

Asked By Ryan Lambert | Mar 19 16
11 Answers

Basement slab reinforcement

Not really a "green building" question per se, but too much knowledge and too good a response time for me to not ask here.

Asked By Jim Tyler | May 19 16
4 Answers

Adding insulation to stucco wall in Los Angeles area home

I'm retrofitting a home near Pasadena, CA and am beginning to look at options for insulating the currently-uninsulated exterior walls and could use some advice. The home was built in 1963, and the wall assembly appears to just be stucco on lath, then building paper, then studs, then drywall. There's no sheathing and no lateral bracing except for some diagonal 2x4s at the corners. (please see photos)

Asked By Chris Stratton | May 17 16
Register for a free account and join the conversation


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