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1 Answer

Flash-and-fill hybrid plus external insulation?

I designed a 2x6 dense-packed cellulose wall, fully sheathed in plywood, plus 3" of external Roxul Cavity Board. Climate Zone 6.

I'm trying to consider alternative wall types due to the added labor costs of external insulation, specifically the complications with fastening and window detailing when getting upwards of 3".

I'm trying to wrap my head around the Flash and Fill system described by Building Science Corp.

In Energy efficiency and durability | Asked By Meri Lewis | Dec 6 14
18 Answers

Exhausted By a House That Saves Energy


An article in the New York Times about a couple who built a very large net-zero house in Vermont, and are now regretting building too large and too complicated.

In General questions | Asked By Jack Woolfe | Dec 4 14
4 Answers

I need help on building some DIY solar projects (portable)

I have done a lot of research and visited many sites but still cannot figure out a few things with a portable solar charging project that I'm working on... I need help with figuring out a solar design to charge say my phone. Is it possible to hookup a wall charger to the output part and it wiil do all the work? Also I'm including batteries and Need to know how to set it up so that the phone will be powered by the panels and battery and the charge will be there only when I plug in the phone... No wasted energy.
So here's all of my knowledge from research:

In General questions | Asked By Shaye Miller | Dec 5 14
27 Answers

Options for garage heat

I would like opinions regarding options for heating a garage. I know, I know, "Why the H@!! are you heating a garage?" will come to mind for many of you. Others will agree that it saves on car repair costs, improves longevity, and allows for storage of "perishables" such as paint cans, bulk canned garden vegetables, and other things wife understandably does not want in house.

Here are the pertinent factors shaping the decision:
* Super-insulated house, Manual J heat load calc gives 12,400 BTU/h (3.6 kW) peak heating requirement (for garage alone)

In Mechanicals | Asked By Kent Jeffery | Nov 20 14
3 Answers

Rigid foam crawlspace insulation — vapor permeance?

We currently have an 18x30 crawlspace that is vented with batt insulation in the floor joists. The crawlspace also connects to a full basement that is 22x30. There is a 2'x2' opening between the crawlspace and the basement that is blocked with plywood, plus a few openings for ductwork and such. There is a radon mitigation system installed on the crawlspace floor, plastic covering that goes up about 10" on the crawlspace walls. HVAC supply and returns, plus plumbing all goes through the crawlspace to that section of the house.

In General questions | Asked By HD S | Dec 4 14
1 Answer

Before people understood the need for a rainscreen gap

These days, conscientious builders usually install siding over a vented rainscreen gap. But back in the old days, however, wood siding was usually nailed directly to the sheathing, with only a layer of asphalt felt or housewrap between the siding and the sheathing.

When siding was installed without a rainscreen gap, the siding took a long time to dry after every rainstorm, and paint didn't last very long.

In General questions | Asked By Martin Holladay | Dec 5 14
3 Answers

Air leak under new glass sliders

We just had new glass sliding doors installed a few months ago (there used to be a very old swinging door in that location, so the hole was enlarged and a new header was put in).

Now, I can feel a lot of cold air leaking in from the bottom. There is no moulding between the laminate floor and the door yet - I am in the process of putting quarter round moulding there, but there is a kick-lock so its taking me a long time to get the cut-outs right to fit around the kick lock.

In Energy efficiency and durability | Asked By Matt Solow | Dec 4 14
1 Answer

Should I fill the unvented soffits with foam?

We have an outbuilding that's about 12 x 13 that we want to turn into year round writing / guest room.
It has a basement where well equipment is located. We've sealed and insulated the ceiling and the floor joist bays above the foundation and covered with 5/8ths wallboard. With a tiny heater that comes on intermittently in the cold weather, the basement stays about 42deg F so the pump doesn't freeze.
We plan to improve the ventilation for the warm months when some condensation occurs.

In Green building techniques | Asked By Rob Cramer | Dec 4 14
11 Answers

Flat roof with no gases or fumes


I am renovating a home in Laguna Beach CA and redoing the roof as well as most of the house. I am highly sensitive to chemicals and the engineer is calling for the following:

1. Ply
2. 4” High Density Rigid Insulation Foam
3. CDX sheeting
4. Mule Hide roof system

I am wondering if you have any suggestions about how to create a gas/vapor barrier so that when the roof heats, I am not exposed to fumes/gasses from the materials. The inside will be finished with 1/2” drywall board.


In Green building techniques | Asked By Kimberly Norton | Dec 2 14
7 Answers

T&G cathedral ceiling with 1/2 inch XPS instead of gypsum wallboard?

Hi out there,

New to this forum, thanks for having me.

Jumping right in. I'm getting ready to insulate and finish a cathedral ceiling in a small cabin (~600 sq ft of lid) and trying to get the details right.

I've been reading the suggested courses of action elsewhere on this site (http://www.greenbuildingadvisor.com/blogs/dept/musings/how-build-insulat...) and here is the plan I'm thinking of at the moment:

In Energy efficiency and durability | Asked By Eric Taylor | Nov 29 14
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