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!


28 Answers

While I love radiators, I hate using fossil fuels

I live in an 1890 Victorian in Southern Pennsylvania, heated by oil. While I love radiators, I hate using fossil fuels! Is there a way to use green technology to use less oil? My methods to date have been uncomfortable - installing a wood stove.

Is there a way of boosting the boiler with green energy? Would geothermal help? I'm newly divorced and ignorant about systems!
Thanks, Susan

Asked By Susan Hanway | Aug 28 16
14 Answers

Log wall spray foam insulation: closed or open cell?

Hi - Man, I'm glad I found your site because I'm torn and need advice for this unusual situation.

Asked By Dave Beller | Aug 30 16
12 Answers

Best HVAC system and suggested improvements

My wife and I are seriously considering building a home on a large lot in a rural area near Rochester, NY (Zone 5). Our general plan is a single story house slab-on-grade house with a partially enclosed courtyard. It poses some challenges, because for its floor area, it has a large and long footprint. I've attached my rough plan for the house, with the hope that I can get some good insight from the GBA crowd.

Asked By John Ranson | Aug 30 16
26 Answers

Mitsubishi minisplits — horizontally ducted

Sorry - I blv I posted the same in another section. Please ignore this question if it's a duplicate.

We are not fans of ductless units. Therefore, we opted for the hidden horizontally ducted units that Mitsubishi provides. Unfortunately, all the Mitsubishi contractors we talked to have never designed a home with these type of units. Plenty of ductless experience.

Asked By Ismail Mohammed | May 21 16
7 Answers

Encapsulated crawl space

About 3 months ago I had my home renovated due to the presence of mold. Renovations included: a new hvac system with new duct work, new hardwood floors and an encapsulated crawl space. The crawl space walls were insulated, insulation removed from the floor and the crawl space was encapsulated in plastic. Air is being provided to the crawl space by the hvac system and a fan was added.

I now have mold (or mildew) on my ceilings. The previous mold was on the floor and walls around vents. The humidity in my house as well as my crawl space is around 69 - 70% .

Asked By Heather Fisher | Aug 30 16
8 Answers

Exterior walls

Zone 5a, Indianapolis
Single story ranch with slab on grade.
4 inch exterior walls
Current construction:
North facing exterior is stone (no weep holes) then 1/2 space then particle board then 2x4 framing with unfaced fiberglass batt then moisture shield ( guessing 3-4 mill regular clear plastic) then 1/2 in dry wall.
All other exterior walls are vinyl siding then particle board then 2x4 framing with unfaced fiberglass batting then moisture shield ( guessing 3-4 mill plastic) then 1/2 in dry wall.

Asked By Edward Kramer | Aug 28 16
6 Answers

Stand-alone infloor cooling system?

I live in northern Canada. It does not get hot very often, but when it does we can get 90-100F for a few weeks or even a month.

I've got full radiant heat system with 8" OC spacing for heat pipes, many zones and a very snazzy pump setup. I've also got 4 HRV's keeping the air moving.

The infloor heat works great, and I find it very efficient.

For the few months of the year where its hot out, the house can get hot. Depending on the room, it can become un-usable. This of course has to do with all the windows and the solar gain. Hey, I like a bright house :-)

Asked By Mark Helmrich | Aug 28 16
12 Answers

Polyiso sandwich with synthetic underlayment

I'm located in Central Texas (China Spring, TX) and am building a house with my wife. The house was originally started by the previous owners and we are replacing and redoing quite a bit of it at the start. We are doing the majority of the work ourselves (taking forever) and we are at the point of finishing the roofing

Asked By Jacob Cox | Aug 24 16
6 Answers

Questions about minisplits and Manual J

Is it possible for someone to provide me with a a manual J online without visiting my home? I cannot find anyone in my area who I feel is qualified.

I can provide whatever info is needed. I've drawn details sketches of all measurements of my home. I've had a blower door test. I know the insulation levels.

We are planning on making improvements over time, however. But I'm interested in a current calculation based on what I have right now. And then as I make improvements I can see how it will adjust the load requirement.

Asked By Ryan O'Rourke | Aug 27 16
21 Answers

How should I address the lack of plywood boxes for my double stud wall rough openings?

Blame it on lack of clarity on my part, but when my framer built my double stud walls he didn't oversize the window rough openings to account for 1/2" plywood sheathing connecting the inner to the outer walls. He figured that this gap could be covered solely with drywall.

What is the disadvantage of not having plywood in this location?

Asked By Adam Peterson | Aug 12 16
Register for a free account and join the conversation


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