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8 Answers

I am looking for the best ideas for a project for my high school Lakesideca class

I have been teaching a green building course to high school kids for 4 years. We design green buildings that are enegy efficient using the 3D BIM software Revit and learn all the latest construction techniques and standards. A lot to learn!
What I am looking for is a good hands on project ideas to apply all the theory and design.

Asked By tim eberhardt | Sep 19 17
2 Answers

Shed roof attachment to a wall with exterior insulation

Good morning all,
I'm interested in your thoughts on the detail of how to attach a roof system to a side wall with the following design details:
2x6 framing with dense-pack cellulose
1/2" ply
soletex mento WRB
1.5" roxul comfortboard 80
3/4 furring strips
lap siding.

for the decks and porch I'm hoping to use "Maine Deck brackets"
I'd prefer not to break the exterior insulation shell.

thanks in advance!

Asked By Thomas Gibson | Sep 21 17
10 Answers

Dense pack cellulose roller: Where to get one?

As a fan of the dense packing method of cellulose in Atlantic Canada, I often run into a few key challenges from contractors:

1 - It's dusty (...not really when dense-packed)

2 - It's different and learning is required.

3 - Not wanting to use strapping (due to added cost) to manage the bulge at 3.5 lb densities.

The common response is to use a hard roller long enough to push the cellulose in. The problem is no one (myself included) knows where to get one? Can you please make some recommendations?

Thank you!


Asked By Mattbrennan4 | Sep 14 17
12 Answers

Location of solar panels on roof

Progress continues on the North Idaho ranch. I'm planning to install a 7 kW grid tie solar system that will have 2 rows of 11 or maybe 12 panels. My roof pitch is 7:12 and my orientation is 10 degrees east of true south with no obstructions. The roof overhangs 3 feet on the section that will have solar panels. I attached a crude depiction of the installation.

Asked By Steve Wolfe | Jul 17 17
4 Answers

Structural support for windows/door with exterior insulation

I am doing a large renovation that will involve adding 3" of rigid foam insulation and I'm installing triple pane Inline Fiberglass windows that are quite heavy and I'm concerned that the methods that I've seen will not have enough structural support for the windows and sliding glass doors. What I have seen is having 3/4 plywood bucks that span the entire opening (from face of exerior insulation +/- furring strips to the face of the interior framing).

Asked By Joshua Rogers | Feb 10 11
9 Answers

Insulating a low-slope roof

Hi Martin,
We are ready here to go ahead with the insulation of our low-slope roof, and decide to go with closed-cell sprayed foam as you recommended.

We had 3 quotes from local company, and 2 of them proposed to shoot 5-6 inches of foam underneath the 1st deck (in green in the following image), assuming we would remove the interior ceiling.

Asked By Francois Desrochers | Sep 6 17
14 Answers

Rock wool vs Wood fiber

I have what I hope is a fairly basic apples to oranges comparison to throw out to the community here.

All else being equal, in a Cross Laminated Timber (CLT) wall with about 8" of exterior insulation under a rainscreen assembly (see attached detail sketch), what might the relative benefits and drawbacks of rigid rock wool (Rockboard 80) insulation and rigid wood fiber insulation (Homatherm or Gutex).

Rockboard 80 data sheet here:

Asked By Ethan T ; Climate Zone 5A ; ~6000HDD | Sep 14 17
3 Answers

Spider Tie concrete house?

Showed up on Facebook today; I didn't find it in a search on GBA.


(I live in a home with an ICF foundation. We had a "miss" on bracing at one location and ended up with a small "bow" that, fortunately, we were able to take out by milling down the EPS. This video seems to infer that no external bracing is required?

Asked By Andrew Bater | Sep 16 17
4 Answers

Air-sealing a metal chimney

Hello GBA community, I have a question about air-sealing an ICC Excel chimney servicing a woodstove in Manitoba, Canada:

Asked By Benjamin Pries | Sep 12 17
7 Answers

Rooftop rigid insulation and solar panels

We are in the design phase of a modest story and a half house in SE Minnesota, zone 6. My builder suggested room in attic trusses for our upper floor, as well as a few inches of closed cell foam on the interior against the roof deck, followed by fiberglass or cellulose. I realized that may not be enough to control moisture in a cold climate and am debating getting a quote on 4 inches vs looking into rigid foam on the outside of the roof deck. One detail that makes it interesting is we are looking at a bonus room above the garage as well. We plan on using metal roofing of some sort.

Asked By Jeffrey O'Donnell | Sep 8 17
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