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11 Answers

Cooling Load Calc for Sizing a Ductless Minisplit

Last winter, I received a heating & cooling load calc for my house. For cooling, the design temp was set to 93F and the indoor temp to 72F, however the ASHRAE design temp for the Detroit area is actually 87F, and I've read that indoor temp for cooling load calc should be set to 75F. In other words, the HVAC guy was erring on the side of oversizing, which apparently is very common.

In General questions | Asked By Nathan Efrusy | Jun 9 17
14 Answers

Heating a well insulated small home with only electricity

Hoping someone can offer recommendations for our current heating situation.

We are building a very efficient cottage that will be lived in year round. We're having an issue on deciding how to heat the home. We will have a backup wood stove but I don't want to rely on the stove. The issue is we won't have access to gas, electric will be our only method for heating besides wood/pellet.


1600Sqft over 3 floors including the basement

R40 Sip Panel Walls
R35 Basement Walls
R60 Sip Panel Roof
Triple Pane Windows
7kW-10 DC Solar System

In Energy efficiency and durability | Asked By DavidCalgary | Jun 19 17
3 Answers

Are Blueridge mini-splits any good?

Hi All,
Does anyone have any experience with Blueridge mini-splits? They seem to be the house brand of Alpine Home Air. Any idea who makes them? Are they any good?

In Mechanicals | Asked By Ben Rush | Jun 20 17
19 Answers

Still Grinding - Uninsulated basement and minisplit problems

It's been about 1 year and 10 months since I started building my house and I'm still grinding. Doing the board and batten siding mixed with cedar is taking some time. Especially since I'm doing it mostly by myself!

In Energy efficiency and durability | Asked By Jimmy Nguyen | May 9 17
3 Answers

Plywood bucks still needed with 1" continuous foam exterior insulation?

Climate zone 3. 2x6 framing 16" o.c. 7/16" OSB sheathing. House wrap. 1" rigid foam. 1x4 furring strips, lap siding.

I've read the Innies or outies article that walks through the steps for an outie window (my preference). Do I need the plywood buck? Is it primarily for air sealing. Are the masonry ties to plywood/stud critical or can the window be installed with just the nailing fin?

In Green building techniques | Asked By Inger Peters | Jun 20 17
8 Answers

Should we tear out our pink fiberglass (above grade) and EPS (below grade)?

Our entire basement (800 sq ft?) has pink batt insulation above grade covered with vapour barrier and then drywall. It doesn't seem terribly damp down there, but I'm just wondering if we really should tear it all out and replace it with spray foam, rigid foam, or Roxul.

Secondly, about 30% of our basement has Expanded Polystyrene Foam (EPS), I think about 1/2"(ish), below grade, covered with drywall. Should we rip all that out as well and redo it with spray foam or rigid foam? Or just leave it?

In Energy efficiency and durability | Asked By Sarah Poulin | Jun 19 17
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
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