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!


7 Answers

How to choose an electric water heater?

I'm looking for an electric hot water heater that is efficient and not too expensive. Not interested in heat pump type, just basic efficient model. The two suppliers we deal with use American or AO Smith. Any thoughts on these? Any other brands? Thanks, Ben

In Energy efficiency and durability | Asked By Ben Williams | May 19 16
2 Answers

Hot water closed loop at 135 degrees F

Hi , I have set up an anaerobic digester at my horse property , I have made a solar heater ( black hosepipe behind some upvc ) to heat it ,for best results I need to get the digester up to max temp 135 deg F , just had my first pump seize up , what of off the shelf pump can cope with that kind of temp , its running water around a closed loop of hosepipes

any and all suggestions welcome

In Mechanicals | Asked By David Lowe | May 19 16
18 Answers

Pretty Good Historic Double Hung....

We're doing a DER on a house in a historic district and tying to balance performance with aesthetic appeal that will be tolerated by the local historic commission.

This is a house in the Boston area and so largely a heating zone.

Is there an 'acceptable' window that gets the obvious thumbs up from our community?
Marvin's next generation double hung looks good and is available with a narrow 5/8th muntin.
I can't find much information on its performance BUT as I begin to (quickly) research are there other specific products within other lines that should be considered.

In Green products and materials | Asked By Edward Cambridge | May 17 16
4 Answers

Wall design

I am adding a small addition to my house and have been struggling with choosing a wall design. I'm trying to find a balance between efficiency, ease of construction, and cost. I was a fan of double stud walls until I read about potential issues with damp sheathing. It occurred to me at some point that if we ventilate ceiling assemblies, why can't we ventilate a wall? Specifically, I'm thinking about ventilation on the inside of the sheathing in addition to a rain screen on the exterior of the sheathing. Has this already been done?

In Green building techniques | Asked By Eric Colbeck | May 19 16
13 Answers

DensShield backerboard - does it need waterproofing membrane?

From what I read in the posts on backerboards in GBA I see several comments on how well RedGard membrane is performing for the shower and tub areas. I also read that DensShield backerboard has a waterproof layer over gypsum core. We chose DensShield for its better environmental attributes. Do we need to apply RedGard over it or would it be an overkill? If we don't use RedGard, what should be done to the seams and corners...?
Thanks,
Lucy

In General questions | Asked By Lucyna de Barbaro | May 18 16
4 Answers

Wood stove chimney flashing

Installing wood stove chimney to go through cathedral ceiling with 12/12 pitch. This is new construction. Roofing material will be galvalume R panel. On the roof, what is the recommended layering system to prevent moisture from entering at the chimney penetration? I have seen metal roof with the flexible high temp boots on top sealed with silicone, and I have seen 12/12 metal roof flashing adhered by sealant directly to the roof sheathing with the roof panels cut around the flashing and sealed , and a combination of many other ways.

In Green building techniques | Asked By Scott Smith | May 16 16
10 Answers

How to construct a window buck for continuous exterior insulation with a rough opening that is too small for the plywood?

My window rough openings are 1/4" wider than my windows per the manufacturers instructions. Problem is, I didn't leave room to install a buck. I found this article on GBA that talks about nailing the windows directly through foam insulation: http://www.greenbuildingadvisor.com/blogs/dept/musings/nailing-window-fl....

In General questions | Asked By Jeremy D | May 15 16
24 Answers

Exterior rigid foam and re-siding project

I'm seeking input and opinion. I'm looking to re-side with the dread vinyl (need the low maintenance for my two story house). My 40 year old post and bean house has interior sheetrock, 3.5" of fiberglass batt insulation with kraft paper, rough cut full 2x4 studs on 24" centers, plywood sheathing (I think 5/8"), paper (a mix of Tyvek and felt), and cedar shingles. Shingles and paper will of course be removed, sheathing inspected in the process. I'm in zone 6.

In Energy efficiency and durability | Asked By Howard Gentler | May 2 16
14 Answers

NanaWall......$$$....Marvin $$$? / Panoramic Door$?

I've been looking at a configuration for a 12' wide opening that we'd like to make into a glass wall.
Nana is the brand everyone is familiar with but preliminary pricing is running $1300 a linear foor PLUS a substantial installation charge (they will actually discount the doors by 10% to 'help' with installation cost (!)

Marvin has their new Scenic Door system
There are other suppliers such as Panoramicdoors DOT com that offer products at a significantly lower price (50%) but I can only find limited feedback and some (Yelp) reviews are not positive

In Green products and materials | Asked By Edward Cambridge | May 18 16
1 Answer

Best way to insulate raised floor over crawlspace

This doesn't seem to exactly correlate with any previous questions that I have found, but feel free to direct me to previous answers I may not have found myself.

In Energy efficiency and durability | Asked By Jim Erdman | May 18 16
Register for a free account and join the conversation


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