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

Mold Remediation

Anyone have mold remediation on a commercial building experience or been/are in the mold remediation industry?

I have a maintenance contract on this building that just started, could smell a strong mildew odor in a unit on the top floor north side of the building when completing a PO. Was doing top floor work in the south side of the building no odor. Slight odor in hall at the midpoint of the building top floor. It was unseasonably warm that day, mid 40's high temp.

Asked By T Carlson | Mar 5 18
11 Answers

Comfort Board 80 vs 110 - density worth extra cost?

For our upcoming house build using 4" of rigid mineral wool we have been quoted for both Roxul comfort board 80 and 110. Over the top of this we will install 2x4 furring and cedar siding.

The 110 has a compressive strength of 1120 PSF at 10% deflection, the 80 is only 439 PSF at 10%, using the 110 will simplify the installation of furring as it will compress less, but I don’t know that the furring installation sub would price their install any differently between the two products. (Furring install not by insulation contractor).

Asked By Chris Armstrong | Nov 16 16
2 Answers

Thermalbuck Insulated Window Bucks

A person on my thread about Roxul Comfortboard vs ZIP-R Sheathing suggested that I use this insulated window buck when using the Roxul system. I never knew this type of product existed, but I think they deserve their own thread.

https://thermalbuck.com/

Anyone have experience using them?

Asked By Scott Wilson | Apr 17 18
2 Answers

Ceiling insulation

I live in South Florida and have an uninsulated open ceiling in a laundry room that used to be an outdoor laundry, it has since been surrounded by a finished living area. It is open to the roof with 6” trusses on 16” centers. The room has a block wall on one side and stud walls to the ceiling on the others so there is no way to vent the space from eaves to ridge. It gets very hot in there and I want to insulate and drywall the ceiling. Should I fill the joist space with insulation or should I leave a gap between the insulation and the roof deck?

Asked By TomProud | Apr 18 18
17 Answers

Wall insulation for a new room addition

I'm thinking about this (not so) future project. One option is 2x6 studding with R-19 (6") fiberglass batts in between studs. To gain more R value and reduce thermal bridging I was thinking of adding probably 2" of type II EPS (4.2 R per inch they say)to the inside of the studs, for about R-27 for the wall. I'm assuming this needs to dry to interior since plywood and/or OSB are pretty impermeable to moisture and would limit drying to the outside. Is that correct, and if so is 2" of EPS adequately permeable for interior drying? I would have sheetrock over EPS.

Asked By Howard Gentler | Apr 16 18
6 Answers

Sealing junction between ceiling drywall sheets

Hi,
I am about to air seal my attic. I will use caulk and polyurethane spray cans to seal air leaks around pipes, electric boxes, chimney, top of walls, ... I was wondering if the junction between the ceiling drywall sheets should also be sealed. Using caulk or polyurethane seem a little overkill (quite a lot of junction to cover $$$) to me and I was wondering if using waterproof paint in those junctions would be a good idea. In the end, I would like to seal all the air except the slow movement of air coming through the drywall itself.
Thank you
Louis

Asked By LongfieldL | Apr 13 18
28 Answers

Are low-e windows dangerous?

I've read a couple of articles that suggest low-e windows can cause fires. It sounds like the low-e coating (or a film, the articles weren't clear) is capable of reflecting and focusing sunlight in a way that can cause materials outside the house to combust. Does anyone have an explanation for what is going on with these windows?

Asked By Steve Knapp CZ 3A Georgia | Apr 1 18
9 Answers

Building on a rock ledge

Building a foundation is usually a pretty straight forward process in my part of the country. But I am considering a small lot that is likely more rock ledge or boulder than soil. The lot has great views in several directions, but I suspect the rock has deterred at least two previous owners from moving forward with their construction plans.

Asked By Steve Knapp CZ 3A Georgia | Apr 15 18
3 Answers

Existing basement framing against concrete

We are looking to insulate our concrete basement foundation walls and the 18" wood framed area between the foundation top and the bottom of the floor above it that includes the sill plate. We are settling on closed cell spray foam.

When the house was built the framing for the exterior basement walls were set up against the concrete foundation. There is anywhere between 0 to 1/4" between the studs and the concrete depending on the studs and the texture of the concrete forms.

Asked By tyman00 | Apr 11 18
17 Answers

Interior walls set on top of rigid foam

I'm building a living space (750sq ft) into a building in zone 6a. The slab has a 6 mil vapor barrier and 2" foam under slab and 2" foam on slab edge. The space is completely empty now. (no interior walls). I cannot tolerate concrete floor to walk around on because of hardness and cold feeling. I would like to lay down another vapor barrier then 2" foam then 2 layers of 1/2 " plywood glued and then finished floor materials. The building sits very high and has crushed rock under slab with 2 ft overhangs and proper landscape grading. I doubt there will be any moisture issues.

Asked By Smokey059 | Apr 11 18
Register for a free account and join the conversation


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