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8 Answers

Minisplit controls?

I'm planning a ducted minisplit system for our renovated large house.
It will be 4 floors (inc basement and cathedral attic) but likely 6+ zones given the size of the house (6k above grade).
Im looking at mitsubishi hyperheat or the fujitsu ducted sustems.

Q. Is there a major difference in the contrils in terms of features / quality?
Q. How do these work in a whole-house heat/cool use? I have wall mounted units currently but the have IR remote controls. What about zoning a whole house?

In Mechanicals | Asked By Edward Cambridge | Jun 13 16
14 Answers

Are there any advantages to using a radiant barrier in an attic?

I'm thinking of installing a radiant barrier in the attic, above the insulation and attached to the bottom of the truss top chord. For my own house.

In Energy efficiency and durability | Asked By Ryck Voisard | Jun 14 16
6 Answers

Exterior closed-cell spray foam to an existing house possibly a slightly different angle

First I apologize as this topic has literally been beat to death..... That said this is a slightly different twist that I cannot find any details on.

Existing house is a 1985 modified split entry. The wall assembly as it exists in the areas I have taken it apart are (from inside out): Paint of various kinds, drywall, foil faced kraft paper (independent of the fiberglass batts), fiberglass batts in a 2x6 wood wall (assuming R-19), fiber board sheathing, probably Tyvek and an old Masonite siding.

In Green building techniques | Asked By Lonney Olson | Jun 10 16
9 Answers

Cost-effective double stud wall with interior wall as load bearing?

For a two-story home with double stud walls in a cold climate, it seems you avoid a lot of thermal bridging if the rafters/TJIs for the second floor are supported by the inside stud wall. I have questions about how to do this "load-bearing inside wall" assembly most cost-effectively. The approach needs to be something a small crew with no crane can implement (so ballon framing is out).

In Green building techniques | Asked By John Huber | Jun 14 16
0 Answers

Lunos e2 vs. TwinFresh Comfo RA1-50-2

Looking for thoughts or feedback on the thru-wall HRV's/ERV's. Specifically the Lunos e2 system vs. the TwinFresh Comfo RA1-50-2.

What I know about the two systems-

They can both work in unison (every 70 seconds or so, they reverse supply and exhaust), during this time the core is regenerating.

The Luno e2 has a remote wall mount datalogger and control head. (an add-on expense $500+). The units (sold in pairs) and are a couple hundred dollars more than two TwinFresh units too.

The TwinFresh has a higher air flow capability, and higher electrical requirement.

In General questions | Asked By Brad Hardie | Jun 14 16
10 Answers

Double stud wall or 2 X 6 wall with foam, need help on decision

My wife and I are getting ready to build a house just on the lake in Chattanooga, TN. I've been going back and forth on construction of the house. The house is 2,700 on one level that will be over a crawlspace. I've gotten a quote going with ICF up to the roofline and am wondering if that is the most effective way to get a super energy efficient envelope that I want. I'm considering a double stud wall system but I'm worried about moisture issues. The house will be all brick for the exterior except for a couple of gables under the front and back porches.

In Energy efficiency and durability | Asked By Matt Holmes | Jun 13 16
2 Answers

ShockWave Drainage and Insulation Board

Does anyone have experience/opinions on ShockWave Drainage and Insulation Board for use as exterior basement insulation?


One house in our area is using it. It seems fairly easy to compress.

In Energy efficiency and durability | Asked By Pat Kiernan | Jun 14 16
9 Answers

Making a renovated building energy efficient

Hi all,

We're in the building phase of completely renovating a chalet in Quebec. We are adding a floor, so the chalet will be two levels, about 1200 square feet. There's a 4' crawl space and no basement (we're on Canadian Shield) and the chalet is facing south at the top of a slope to the lake. The contractor has done a number of similar renovations and is great to work with. I'm not an expert and don't want to exasperate him with suggestions, but since concrete is being poured in a couple of weeks, and insulating and windows have not been installed it was suggested I post here.

In Energy efficiency and durability | Asked By David M | Jun 12 16
9 Answers

Insulating basement stud wall

There's a ton of information out there regarding how to insulate concrete walls. My basement (actually I think it's technically a really tall crawlspace with vents) has wooden stud walls sitting on concrete walls where the wall goes above grade (house is built into a hill). I don't have traditional rim joists on 3 sides of the house, it's just a half wooden wall. How could I insulate and seal the stud part of the wall without resorting to spray foam? Could the rigid foam boards be attached in whole sheets directly to the studs?

In Green building techniques | Asked By David Clark | Jun 12 16
2 Answers

Advice on hip roof venting and underlayment choice

Zone 6A
Ranch house 50' x 30'
Hip roof 6/12 pitch
Attic has been air sealed and insulated. Brief details:
All existing fiberglass batting removed.
Air sealing completed.
The existing 2x8 rafters were birdsmouth cut at the top plate leaving about 4" between the sheathing and top plate. Not enough room for soffit ventilation and proper air sealing and insulation in this critical area. So closed-cell spray foam was installed in lifts building up to 9" thick.
18" of cellulose installed elsewhere.

Time now for reroofing before adding PV.

In General questions | Asked By Brent Mellen | Jun 10 16
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