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!

19 Answers

How does someone cancel subscription when there seems to be no way out??

Could someone guide me in the cancellation of membership? it doesn't seem like it is possible to do so.

Thank you

In General questions | Asked By James Someone | May 27 17
10 Answers

Insulation below the camp

OK -- I don't know what I don't know, and basically I need advice on how to insulate the underneath or a camp -- we live in Upstate NY, and we are building a camp on piers using cement tubes -- we are torn on how to keep things from freezing. I know we need some type of barrier to keep all the unwanted guests out from under the camp, so some type of skirt needs to be added, but do we put insulation on the inside of those, to keep thins "warm" or do we add insulation to between the floor joist and then put OSB up to keep it enclosed -- or a combination of both or all or what?

In General questions | Asked By AJAYP66 | Nov 29 17
3 Answers

Any potential problems with unexpected overkill?

I’m nearing completion on a new house build and I’ve asked the builder to take some measures above and beyond his usual process in the interest of comfort and energy efficiency (exterior rigid insulation, conditioned crawl, extra air sealing measures on exterior walls, etc...). I had also asked for air sealing in the attic around the penetrations and top plates. I’m not sure if there was a miscommunication but rather than focused air sealing they had the insulator spray a thin (1/2-1”) layer of closed cell spray foam over the entire roof deck!

In Energy efficiency and durability | Asked By Rich Singleton | Nov 29 17
13 Answers

How can I find an efficient electric oven for my kitchen?

My electrical oven adds a tremendous amount of heat to the house. The top surface, beneath the broiler pans, is 175 degrees when the oven is at 350. The sides of the oven are at 125 degrees.

The expensive ovens don't seem any better. A GE smoothtop range I used in a rental condo blew air through vents at the top of the door - it seemed to be for keeping the door cool to prevent folks from burning themselves on the door. The fan continued to operate for about 15 minutes after the oven was turned off.

In Green products and materials | Asked By Kathy Reynolds | Mar 6 14
1 Answer

VanEE ventilation

My landlord wants this unit left on but it blows cold air full blast into my place. I mean freezing air very forcefully. I closed the vents but the cold air is freezing on my floors. I have electric wall units not a blowing furnace. Its set to comfortable humidity. I have turned it off due to being cold. The windows are very wet with condensation. Our outdoor temp right now is - 7 C.
Do you have any ideas about whats going on here - doesnt seem normal to me. I am used to gas furnaces so this has me stumped.
Thank you

In General questions | Asked By MarianPurcell | Nov 29 17
0 Answers

Digital vs. VRF Scroll Compressors?

I'm looking at two different heat pumps, one using a digital scroll and the other a VRF (variable speed) scroll compressor.

The digital scroll compressor modulates output by separating the scrolls on a duty cycle, essentially a mechanical way of turning the compressor on/off as necessary while keeping the motor running. Modulation is from 100-10%.

The VRF scroll compressor modulates output by varying the speed of the compressor. Modulation is from 100-30%.

In Mechanicals | Asked By Lance Peters | Nov 29 17
9 Answers

Long-term solution for a humidity issue?

I am trying to identify a long-term solution to address high humidities in a recently purchased house. The circa 2015 house is almost 1900 ft2, including finished first and second stories and a walkout basement of which ~40% is finished. The basement was poured using ICFs (2.5” foam insulation on either side of the concrete walls) and has 2” of foam under the slab. The framed portion of the walkout basement was built using 2x8s and insulated with R-30 roxul between the studs. The walls on the first and second floors use 2x6 framing and include R-23 roxul between the studs.

In Energy efficiency and durability | Asked By Rob Shuman | Nov 28 17
1 Answer

HVAC duct insulation check by cutting wrap

Is it appropriate to check duct insulation by cutting its wrap 1 ft square piece? I think it will not be as per SMACNA.

In Mechanicals | Asked By M Bilal Sadiq | Nov 28 17
5 Answers

Open-cell foam with Tyvek?


We will be starting a new home next year. We are located in the mid lower peninsula of Michigan. We are going with the standard 2x6 exterior framed wall, with sheathing, Tyvek, and vinyl siding on top of that. I am pretty much convinced of open cell foam inside the walls.

My question is, using open cell foam is the Tyvek a good idea for the external face of the walls (just under the vinyl siding? Any issues with this?

Thank you.

In Green products and materials | Asked By css1813 | Nov 28 17
19 Answers

Building a new house in the Northeast: What heating system for cost and efficiency?

Hi - we will be building a new approx 2000 sqft modular home in Zone 4 Marine / Zone 5 (think its the 4 Marine).

The builder has recommended standard fiberglass wall insulation, says because it's modular it will be tighter than stick-built, but can upgrade from new code with Upgrading to R 49 in attic (from R 38) and adding R7 rigid foam on outside. I understand that this is still short of the pretty good house standards, but it might be up to the code plus. We will also probably finish the basement with plenty of insulation (although how much is plenty).

In Mechanicals | Asked By Noahclem | Nov 26 17
Register for a free account and join the conversation

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