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!


10 Answers

Exterior Rigid Foam Under Sheathing?

In my local area there is a green building consultant that recommends a CI panel which is basically EPS foam glued to OSB. The way this is installed would be the OSB to the exterior. Almost every house I see with exterior rigid foam in my online wonderings is covered with blue and pink XPS, the OSB sheathing is nailed directly to the studs and is completely covered with the rigid foam. This leads me to the following questions:

- Is anyone familiar with these kind of CI panels?

Asked By Joshua Greisen | Dec 8 16
0 Answers

Common Issues Can be Prevented When You Outsource Software Development

Game QA is a extremely important aspect of the entire process of game technology. This is done both during and individuals coding and programming of one's game. Make sure that you debug all of code quit any bugs from slipping in. Serplify Review Also, test all elements and modules with the game end up being sure which work together well of which the game is playable. By doing which will ensure that you are releasing an excellent game.

Asked By Tanya Bohn | Jan 19 17
2 Answers

Vapor Barrier on top of SIP floor?

We are working out the details for the construction of our new house in the Pacific Northwest. Our architect and structural engineer have specified a 9 1/4" SIP floor for the 1st floor. Since we will be building in a flood zone, our foundation will be an open design with concrete columns extending from a mat foundation. Horizontal beams will sit on top of the columns and the SIP panels will sit on top of the beams. The structural engineer has specified a factory treatment of "bluewood" preservative to the bottom face of the SIP panels.

Asked By Kevin Camfield | Jan 17 17
9 Answers

Another "help me design a wall" thread

I've read wall build articles here but I'm still ambiguous as to the placement of barriers. I've also watched Dana's series titled, "Extreme 10 foot or less snowy knoll patch skiing", but couldn't find any relevant information there.

Zone 5. Inside to out: (sealed?) Drywall | 2X6 studs sealed with Ecoseal and filled with dense pack | either OSB or ZIP taped | 3" poly foam taped | rain screen, vinyl siding.

From what I've learned here this wall will need to dry to the interior.

a few questions, if I may?

Asked By Drew Baden | Dec 28 16
5 Answers

Fiberglass and Cellulose performing differently in attic

In our vented attic, we specified 18" of blown-in cellulose. In one particular location, the insulation contractors were called back to redo an area that was not covered. When it got cold outside, I noticed that the ceiling in that area was noticeably colder than in other areas. Suspecting that the insulation contractor didn't actually fix it, the builder and I went to the attic today to check. They had attempted a fix. Instead of putting cellulose in the problem area, they had installed fiberglass batts. The batts looked to be about the same thickness as the cellulose.

Asked By Reid Baldwin | Jan 17 17
8 Answers

Mount outdoor unit on the wall or on the ground?

I am close to installing 3 fujitsu mini split units at our home under construction. Two outdoor units will be installed near each other, with the third installed in a different area of the house. The HVAC installer asked if I wanted to mount them on the wall or on the ground. I can't decide which I would prefer. Any thoughts on the pros and cons of each?

I live in central KY, zone 4A. We don't get much deep snow around here, maybe once every 10-20 years.

Asked By Clay Whitenack | Jan 18 17
4 Answers

Thermal breaks for window bucks in double stud walls

We'll be buliding double stud walls for a new house, with the inner wall being structural (the outer wall will consist of modified Larsen trusses). Total wall thickness will be around 16" and windows will be "in-betweenies". This will be my first double-stud wall house and I'm working in the wall details trying to minimze thermal bridging.

Asked By Chris Chenier | Jan 18 17
8 Answers

Exterior wall polyiso worth it?

I live in central Texas and I'm debating whether adding 3/4" Polyiso to the outside of my exterior walls. would be worth the cost. I originally planned on it, but since my wife and I are doing the majority of the work, it has come down to just not having the time (we both work full time jobs, plus a bit more), and the initial cost of it.

Asked By Jacob Cox | Jan 17 17
2 Answers

How thick a layer of closed cell spray foam under roof deck?

Our roof has 4" of rigid board closed cell foam with OSB (Atlas Nailbase) installed above the roof deck, but the seams between the sheets of foam were not sealed, as one can see in the attached picture. For those areas I can access, I started spraying closed cell foam on the underside of the roof deck - how thick a layer of spray foam under the roof deck do I need to have for reasonable insurance against moisture condensation at the seams of the Atlas OSB??

Asked By Jim Berry | Jan 18 17
10 Answers

Construction Docs, quick review please

It's been a long journey but we're at the stage to begin construction in the next couple months. My architects did a stellar job combining our aesthetic vision with green energy design. For my own peace of mind I am hoping to have the experts here take a look at the construction details. Let me (and my builder, who will be dropping in on this thread) know if you have any major concerns with the construction details. The house is in 5A, oriented East-West (roof slope facing south). There is a wrap around porch, a root cellar beneath one side of the porch, and a walk out basement (south side).

Asked By Clara Kim | Jan 16 17
Register for a free account and join the conversation


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