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!


3 Answers

Nebraska — unvented attic with high humidity

Last year after a severe hailstorm the attic insulation and the entire roof deck of my 1600 sqft ranch style home in Fort Calhoun, NE was replaced. With the replacement we upgraded the insulation to Open Cell Icynene spray foam on roof decking. The spray foam is at least 6-8 inches on the roof, and covers the sidewalls, soffits, and attached garage ceiling. This completely closes in the attic to the thermal envelope of the house. I've been monitoring the relative humidity levels of the house for the last year.

In GBA Pro help | Asked By Nick Schuler | Jun 28 15
1 Answer

Spray closed-cell flat roof or not? Old brick walls - spray foam?

Greetings, Im currently renovating a 100 yr old rowhome end unit and adding a large framed addition that will have a flat roof deck surface that will be coated with FRP over OSB ;2x12 joists( no venting /warm roof) -there are so many controversial articles on how to properly insulate to avoid moisture entrapment it is dizzying..

In Green building techniques | Asked By Darron Zimmer | Jul 3 15
12 Answers

Is my 5000 BTU LG 10 year old window unit significantly inefficient ?

My wife says so, in comparison with similar modern window units. She wants it replaced. The unit runs on all work days, during summer work hours, in my home office in San Antonio, Texas. San Antonio summers are hot, but not as hot as north Texas, as an example comparison. My question is whether efficiency advances in 10 years have made a big difference for small window units.

I tried to search, but every search returned hundreds of irrelevant topics.

In General questions | Asked By Weldon Cabaniss | Jun 28 15
17 Answers

Deep energy retrofit — Envelope upgrade questions

We are well into the process of a deep energy retrofit for our 2,700 sq. ft. house in NYC suburbs, zone 4/5A. The house is a typical 1988 contemporary with 2x6" wood frame construction, builder grade, sloppy subs, code minimum and 25 years of neglect. Long story short, we are currently replacing the roof, windows, doors, siding and HVAC. Before we started renovations, the blower door test result of just under 11 ACH50, proved that the envelope could be improved, so that is now our focus.

In Green building techniques | Asked By Andrew Wuench | Mar 31 15
1 Answer

Intus finishes: Any chemists or PVC film experts out there?

About to get quotes for 2 jobs on Intus vinyl windows. Never heard of this technology and its pretty amazing how dark they are offering for some of their exterior color selections in vinyl. I will recommend staying on the lighter side to be safer but does anyone have any opinions on this film technology and color choices that Intus is using?

http://www.intuswindows.com/products/windows-u-pvc-arcade/

Click on "colors" for description of the film technology.

In Green products and materials | Asked By Brian Knight | Jul 2 15
3 Answers

Details about drywall under tongue and groove as an air barrier

I have read often on gba about the importance of using an air barrier under tongue and groove and I may be over thinking it but it seems that 1/2" ultralight has the potential for more air leaks around nail penetrations due to occasional voids in ultralight and that 1/2" could more likely bust around nail penetrations and let air in versus 5/8" but before I wear myself out hanging 77 lb sheets I figured I should ask an expert.

Thanks,

Matt

In GBA Pro help | Asked By Matthew Seabolt | Jul 1 15
1 Answer

Where to put the water barrier?

Hi,
I'm going to retrofit rigid foam over a log home in Vermont. The logs are 6 inch pine logs, that have an R value of about 9, they have a clapboard cut on the outside so the house will not appear any different with a 3 inch layer of foam insulation with a rain screen and clapboard.

My question is about where to put the tyvek, on the out side of the foam or under the foam? We are replacing all the windows and doors. It would seem to me that the tyvek belongs on the outside of the foam and over the flanges of the new windows and doors.

In GBA Pro help | Asked By Thomas Gardner | Jul 2 15
3 Answers

Can a feature be added to e-mail on a reply?

If i want to follow a conversation, I have to come back to it and sometimes it ends up on the second or third page. It would be very convenient that once I reply to someone's question, I get an e-mail when it gets replied to by someone else.

In General questions | Asked By Alan B | Jul 1 15
2 Answers

Older home (1950s) smells of mildew...

I purchased a home in late 2009 and have been trying to get rid of a heavy mildew odor. Last week I discovered the seller had put vinyl siding over two layers of other siding. Underneath the vinyl was a layer of extremely damaged Boise Cascade panel siding. It was crumbling and had large holes in multiple places (no house wrap). Behind the holes I discovered clear plastic sheeting and underneath that was cedar lap siding. I continued on down to the Buffalo board that was somewhat warped and had a strong mildew odor.

In General questions | Asked By Terri Goodheart | Jul 1 15
5 Answers

Air sealing exterior walls in a benign climate

Hello Martin,
I am removing and replacing the siding on an old Victorian located in Berkeley, CA which I believe is climate zone 3. After stripping off the old layers of siding, we will insulate, install plywood sheathing, (nailed at 4 at eh edges and 6 in the field for seismic stiffness), and then a drainable house wrap and fiber cement siding.

In Green building techniques | Asked By Craig McCaleb | Jun 20 15
Register for a free account and join the conversation


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