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27 Answers

Sizing minisplits for adequate heating & cooling in a cold-climate Passive House

We are building a 2300 square foot Passive House in the midcoast area of Maine and are having trouble choosing and properly sizing our mini splits for both adequate heating and cooling. We live in an area where of course it gets below zero many times during the winter. So we are limited (I think) to the brand of mini-split we can choose from.

In PassivHaus | Asked By CathrynJones | Apr 11 15
9 Answers

Window flashing for new construction

Good morning,
I am getting ready to install windows(aluminum clad) on my new construction and would appreciate help figuring out the flashing details.
The exterior walls are made of gigacrete wall panels. The panels are basically steel studs encased in 8" thick eps. The walls will get a coating of stuccomax(gigacrete'a proprietary exterior coating). There is 3" of eps on the outside of the studs so essentially the windows will be inset a little over 3".

I am attaching a few images so the wall components/window openings can be better understood.

In GBA Pro help | Asked By asim majeed | Apr 6 15
5 Answers

How much of a 2 x 6 plate has to be on the stem wall?

The real question is whether to use 6 in or 8 in blocks for my stem wall. Stem wall is 24 in high, this is slab construction.

The wall is metal, membrane, 1.5 in ISO, 5/8 OSB, 6 in plate, 5/8 drywall, trim.

If I use a 6 in block and line the outside of the ISO with the outside of the block, that puts only about 3.5 in of the plate on the block. Will this work? The good part of this system is that the 3 in of styrene on the inside of the stem wall can be let untouched and thereby give me a good thermal break between the floor and the block.

In GBA Pro help | Asked By Tooger Smith | Apr 16 15
5 Answers

Best HVAC options for large house in zone 5a.

I have a custom house with 3930 sq/ft of conditioned space in a development in northern Idaho, (Zone 5a). The basement is planned to be Logix Platinum ICFs with R-28, the main and upper floors planned as 2x6 advanced framing walls with cellulose, 7/16" OSB, Tamlyn Drainable Housewrap, 1.5" of Terrafoam EPS, and fiber cement siding.
I'm hoping to get the owner to agree to spray foam the attic sheeting to condition it (R-38 min.)
The basement is 1830 sq/ft including a conditioned space under a large garage. The upper two floors of living space are 1050 sq/ft each.

In GBA Pro help | Asked By Nethaniel Ealy | Apr 15 15
3 Answers

Various spray foam companies

Hello,

Would like to know if there any significant differences between the spray foam made by various companies?
We have two vendors in our area and one uses Bayer for Open cell and Dow for Closed cell, while the other vendor uses, Premium and Johns Manville?

Help greatly appreciated

Thanks

In General questions | Asked By Yasir Khan | Apr 15 15
1 Answer

How should I insulate cavities underneath a subfloor?

Part of our dining room is built over a small area that consists of 2x12 joists that sit directly on concrete. The reason this small area was built this way was because it was an extension to an old foundation.
What is the best way to insulate the space between the joists (i.e., the cavities)? This area becomes quite cold because it is on the outside edge of the house. My concern is that moisture will build up under the subfloor.

In General questions | Asked By Shlomo drexler | Apr 15 15
1 Answer

New Home - Wall Assembly Review

I'm building my first custom home this summer and could use GBA's collective wisdom to vet the wall assemblies.

Stats:
Zone 5a
Logix Platinum ICF basement (R-28)
2x6 advanced framing, blown cellulose, 7/16" OSB, Tamlyn Drainable WRB, 1.5" Terrafoan EPS, Fiber cement or steel siding.
Conditioned attic with min. R-38 closed cell spray foam
"Innie" window placement

Questions:
Will placing the drainable WRB between the sheeting and EPS cause air flow that will serve to defeat the EPS insulation?
Does this mean I should move to an "Outie" window placement?

In Plans Review | Asked By Nethaniel Ealy | Apr 16 15
22 Answers

Can a house be built without wood?

A thought experiment, no wood beams, studs, sheathing, subfloor, rafters or anything else that is part of the house (wood furniture or other possessions are fine, we are far from a paperless society). With a price comparable or at most 50% more then a conventional house how would one build a house with a basement, main floor, second floor if possible, attic and roof?

Of course it should be insulated, the 5/10/20/40/60 would be fine, and would have the usual amenities, washer/dryer, fridge/stove, pluming, electricity etc.

In Energy efficiency and durability | Asked By Alan B | Apr 11 15
5 Answers

Multisplit temperature control per zone

I am considering a multisplit heatpump system for our 3000 s.f. two-story renovation located in Chicago, Zone 5. I like the idea of a multisplit system for its high efficiency and zone control. I would like to provide 1 unit per bedroom using ducted interior units that supply conditioned air to each bedroom.

In Mechanicals | Asked By AlokKhuntia | Apr 14 15
4 Answers

WRB advice

Finishing several additions to a coastal home in South Georgia.
Basically...plywood, wrb, vented furring strips, cedar shingle sidewall.
Due to the hot summer we plan to go north for 4 months and won't be able to completely finish the exterior. Looks like the WRB applied is about as far as I can get.. So...what wrb to use.
I know these products have limited "uncover" time.
Thinking a liquid applied WRB might be the way to go...considering wind, ripping, etc.
Any thoughts......thanks

In GBA Pro help | Asked By Robert Brown | Apr 15 15
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