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!


1 Answer

Is foam-only window installation OK?

We have a solid (structural) brick house and want to install aluminum clad wood windows without trim. We don't any buck, flange, clips, or screws to be visible, so we are thinking foam-only between the window and the masonry opening.

Will this work to firmly hold the window in place, and act as a weather barrier?

In Green building techniques | Asked By 2175kirby | Jun 20 17
10 Answers

How to fix a condensation problem possibly caused by closed-cell foam in the roof?

We have a mid-century modern home with a very low roof pitch. We pulled off the roof, blew 6 inches of closed cell insulation between the rafters and then put on new plywood and a new rubber roof. We have bathroom ceiling fans that vent through the roof, canned lights in the living room, and a light fixture that's set into the ceiling in the dining room.

In General questions | Asked By Midcentury Modern | Jun 19 17
21 Answers

Installing LP Smartside over foam and 24 inch centers

We’re building a new home (SW Virginia) with 2x6 studs on 24 inch centers. We had hoped to use 1.5 to 2 inches of EPS rigid foam to the exterior of the sheathing, then 3/4 inch x 4 inch plywood furring strips, then LP Smartside lap siding. We knew we had to use the 76 series Smartside product for the 24 inch centers. Then I discovered that LP’s installation instructions specify 1.5 inch x 3.5 inch furring strips for foam greater than 1 inch in thickness, so I guess that would basically mean a 2 x 4 stud for every 2x6 stud in the wall.

In Green building techniques | Asked By William Costello | Feb 17 17
5 Answers

What's the best assembly for an unvented attic roof?

We're about ready to break ground on a new home in Northern Virginia (Climate Zone 4) and we're planning on having an unvented attic. The assembly I'm considering 5/8" Zip-System roof sheathing with Henry permiable underlayment, cedar breather and then cedar shakes. My thinking was that the combo of Zip and Henry would be a 'belt-and-suspenders' approach to protect against water since I'll have closed-cell spray foam on the underside. I also wanted vapor permiable membranes and cedar breather to increase the drying potential of the sheathing. Thoughts?

In General questions | Asked By Michael Winn | Jun 17 17
10 Answers

Pour different slump concrete into the same foundation?

I want to pour a monolithic concrete slab foundation. plan to pour less-slump concrete in the foot sections and in the slab, pour the high-slump concrete.

is this good? if yes, what are the recommended slump values.

many thanks.

Mike

In General questions | Asked By Mikeso | Jun 16 17
1 Answer

Exterior foundation insulation and basement windows

New build, CZ 6A (Ottawa ON)

I would like to insulate the above-grade portion of my basement walls to at least a foot below grade, in addition to the code required interior insulation (R20 with no thermal bridging), most likely a layer of EPS foam board with a framed 2x4 wall and cellulose or fiberglass.

Assuming an 8" thick foundation wall, how do you suggest approaching the insulation details around basement windows? Can the exterior insulation wrap inside the rough opening and connect with the interior insulation? If so, how is the window installed onto the insulation?

In Energy efficiency and durability | Asked By Lance Peters | Jun 19 17
0 Answers

Global climate change solutions

Paul Hawken has written a book that identifies the most effective solutions to our climate change crisis.

The New York Times has posted a quiz on this topic -- sure, it's a gimmick, and designed to be tricky, but it's worth reading. Here is the link: How Much Do You Know About Solving Global Warming?

Here is the link to the list developed by Paul Hawken: Summary of Solutions.

In General questions | Asked By Martin Holladay | Jun 19 17
6 Answers

Roxul insulation

Does Roxul come with a paper barrier? Do I have to you put a vapor barrier down in the attic before I put down the Roxul?

In Green products and materials | Asked By Tool1 | Jun 16 17
4 Answers

Effect on mean radiant surface temperature by air heaters

I'm weighing up the pros and cons of hydronic heating versus multi split heat pumps.

Obviously heat pumps work by heating and circulating air within a space. Hydronic heating, depending on the type and position of emitters will radiate heat to people and room surfaces as well as (to some degree) heat some air and cause convection loops.

In General questions | Asked By George Kantianis | Jun 18 17
3 Answers

Flooring & Indoor Air Quality

Any recommendations for quality, affordable (< $4 / sqr ft) wood or laminate flooring that does not compromise indoor air quality? Few more specific questions:
1. Are California / "FloorScore" standards good enough?
2. "GreenGuard" appears to be more stringent - true?

I'm fine with laminate or engineered wood, click install / floating is fine. My criteria, in order, are:
- "not toxic". i.e. low/no formaldehyde / VOCs
- quality: looks good, doesn't squeak or cause more noise than a more expensive product, durable for kids/pets, etc.

In Green products and materials | Asked By Matt Draper | Jun 16 17
Register for a free account and join the conversation


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