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2 Answers

Insulate gaps in rough openings

Would it be a good option to make rough openings 1" or 1 1/8" larger on each side and fill that gap with rigid foam rather than using spray foam or stuffing fibreglass in the gaps? or is there any advantage / disadvantage to this method?

In Energy efficiency and durability | Asked By User-6850466 | Jun 14 17
6 Answers

Wall Cavity Insulation

I know that most people on this web site rave about dense packed cellulose, but why? If the air barrier characteristic is not relevant (as in a REMOTE or PERSIST wall), will any equal R-value insulation do?
Would the most significant advantage of dense pack be the lack of settling over time? Is that a problem with other blown in types of insulation, even the glue/wet cellulose? Our Habitat for Humanity homes in the area use blown in rock wool with a glue/water spray. The stuff seems moderately stuff when they are done, but will that change over time> Will it settle?

In Energy efficiency and durability | Asked By Steve Young | Jun 12 17
1 Answer

Measuring vent area for whole house fan

Considering installing a 6000 CFM whole house fan in our 3200 square foot house. The fan we are considering is the QuietCool QC-CL-6400, and the manufacturer recommends 8 square feet of vent area in the attic.

Two questions:

1. What vents can I count towards the required vent area? I would think, with the attic pressurized, any "official" opening (gable vents, ridge vent, soffit vents, etc.) could be counted. Is this true?

In Mechanicals | Asked By Matt Culik | Jun 13 17
3 Answers

Garage on a slope

We are building on a steep slope in the mountains of NC. The house is long and thin out of necessity, with the garage on one end. One issue I had with the plan(which is early in the process now)was the garage on the first level with a huge space beneath it on the lower level(which has 2 bedrooms as well). I don't need the extra space, nor do I want to insulate it and condition it forevermore. I think the insulation detail(the poured concrete pan, the steel beams, etc.) will be tough. So, I was looking around at alternatives and found the solution in the picture I attached.

In General questions | Asked By Kevin Spellman | Jun 13 17
10 Answers

Small House (12x16) Slab on Grade vs Crawlspace Foundation

I am designing an accessory unit that will be 12' x 16' and I had a friend recommend that I consider a crawlspace for the foundation instead of a slab on grade. My gut (and research) tells me that a slab with proper foam insulation detailing underneath would be more efficient to heat (cold, dry climate). As I discussed some of the mechanical details with him and mentioned electric tankless DHW (1 kitchen sink and 1 shower with not a huge risk for simultaneous use...

In General questions | Asked By John Brown | Jun 10 17
1 Answer

How thick to encapsulate ducts in a vented attic?

I was wondering if there are any resources that provide guidance as to how much closed cell spray foam to use when encapsulating ducts in a vented attic? I haven't been able to locate any specific guidance on the matter. Most seem to recommend a minimum thickness of 1.5", but this seems to be based more on providing enough foam to ensure an adequate vapor barrier/air seal. I don't know if there is a cost/benefit rationale for increasing the thickness further, but certainly there must be a point of diminishing return.

In Energy efficiency and durability | Asked By Rich Singleton | Jun 12 17
1 Answer

Best way to get air movement in older homes with central air

My home is over 100 years old, it has central air. First level is very cool second and third level are just the opposite. Each level has cool air returns, but not if the right size or amount for levels.

Another question can one air return work for two bedroom if in the same wall.

In General questions | Asked By infohungry | Jun 12 17
3 Answers

Any experts in Title 24, Part 6 out there?

In replacing a wall and adding insulation (home was built in 1961 and currently has no wall insulation) I am also adding two small windows to this south-facing wall. Because I'm adding windows, I need to comply with either the prescriptive requirements of Title 24 or the performance requirements. Because I'm not adding conditioned space, I cannot demonstrate performance based only on the new space, but would have to demonstrate it on the whole house which is completely impossible without a gut remodel.

In Building Code Questions | Asked By Domenico Perrella | Jun 11 17
9 Answers

Batt insulation over spray foam in a cathedral ceiling?

I just had 3 inches of closed cell foam (R21) installed on inside of my cathedral ceiling (new const.) and was planning on adding R19 batt fiberglass over the spray foam. The spray foam contractor says I'm wasting my money since the closed cell foam is 97% efficient. Now,I'm confused. From my research, I thought I needed at least an R40 of insulation in a cathedral ceiling in my zone. They said just skip the fiberglass and install the tongue and groove because I wont see an benefit. I'm skeptical but not sure. Any help would be appreciated.

In Energy efficiency and durability | Asked By Alan Buckley | Jun 11 17
8 Answers

Your opinions on my 1955 brick ranch?

Hi, I'm looking to develop a plan as to how to convert my recently aquired home into a comfortable, reasonably energy efficient place to spend the next few decades.

here is the overview.

In Energy efficiency and durability | Asked By SlateRun | Jun 10 17
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