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10 Answers

Wall assembly advice?

Curious what people think of the following wall assembly:

- 1/2 drywall w/ vapour barrier primer (also ADA).
- 2x6 wood frame wall w/ roxul or dense-pack cellulose.
- SONOclimat R6 structural fiberboard w/ Neopor EPS.
- Delta-Dry rainscreen.
- Horizontal 1x3 strapping @ 24" O.C.
- Combination of vertical wood lap siding and pre-finished metal siding.

Zone 6 build in interior British Columbia, Canada... area is a designated a temperate inland rainforest.

Thanks in advance!

In General questions | Asked By Daryl Ross | Feb 23 14
16 Answers

Add batts above ceiling to Icynene on roof deck?

We had our attic treated with 5 -6 inches of Icynene (an open-cell foam product). The team vacuumed out the very aged blown in cellulose that was in the attic.

While we have seen our bills go down, I am wondering if we might be even more comfortable with some simple rolls of fiberglass insulation added between the ceiling joists. Even though our bills have gone down, I hate the thought of sending heat up into the attic.

Opinions? Thank you for your time :)

In Energy efficiency and durability | Asked By Rachel Stutsman | Feb 24 14
8 Answers

Point source ERV (or HRV) and mixing

In my home, the whole basement has been renovated from a leaky post ww2 bungalow(Southern Ontario), making it much tighter than it used to be. The ventilation on the main floor is and has always been old, leaky and sufficient, but it is the basement where IAQ needs improvement.

With a forced air HVAC, Dr. Lstibrek says that mixing occurs anyway in supply/exhaust and balanced systems in this great article (if i read this correctly):
http://www.greenbuildingadvisor.com/blogs/dept/building-science/intervie....

In Mechanicals | Asked By cory b | Feb 24 14
4 Answers

Best approach to deep energy retrofit the stud bays in a brick home?

I have a three-story brick home in climate zone 5 with interior plaster walls on both wood and metal lathe-at least 2 inch thick in many areas based on prior renovation of a bedroom. Home was built in 1920 without stud bay insulation.

In Energy efficiency and durability | Asked By W. Timothy Ward | Feb 23 14
4 Answers

Thoughts on PERSIST construction in Chattanooga, zone 4a

I'm designing my home using the PERSIST technique and would like input on insulation ratios that are suitable for my climate zone. I'm in Chattanooga, climate zone 4a, with 3587 heating degree days and 1544 cooling degree days.
Practically speaking, we have 3 months of trying to stay warm, and 8 months of desperately trying to stay cool.
My plan is a 1200 square foot, 2 story, flat-roofed house with a simple footprint, oriented for passive heating, windows placed accordingly.

In Green building techniques | Asked By Myles Freeman | Feb 25 14
6 Answers

Strapping for dense pack cellulose

Looking for recommendations on the correct strapping spacing (12" or 16") to help prevent bulging with a dense pack cellulose installation on walls. We will be using Insulweb over 8" cavities, 16" on center framing.

In GBA Pro help | Asked By jessie pratt | Feb 25 14
4 Answers

Where are commercially available VIG windows? Are they vaporware?

When I first read about vacuum-insulated glazing (VIG) several years ago, I got really excited; R-10+ windows!! I've been checking every couple of months since to see if they were commercially available and they STILL don't appear to be.

I've got my 100+ year old home almost up to passive house standards with air sealing/insulation. The foreclosed-upon house flippers that we bought our home from installed the cheapest builders grade dual pane windows they could. These are the weakest link in our home's energy efficency.

In Green products and materials | Asked By David D | Dec 12 13
2 Answers

Zip-R sheathing and spray foam?

I am looking to build my house in Birmingham, AL, Zone 3. I plan on using Zip-R 1 1/2" (possible 1" due to cost) and use 2x6 advance framing minus the single top plate. The exterior will have brick veneer.

My question is about using spray foam in conjunction with the Zip R polyiso. Is it chemically compatible? Thought on just filling up 24" cavities with open cell vs 2" CC and R15 batts?

I am a little worried about the CC not allowing drying to the inside, however, I'm not sure, since it will be bonding with the polyiso.

In Energy efficiency and durability | Asked By Paul Pankey III | Feb 24 14
23 Answers

With $15,000 would you buy PV or improve your envelope?

Last night I went to an informational meeting sponsored by Solarize CT. This organization negotiates with solar companies to reduce installation costs for PV panels. They keep lowering the price in accord with how many people sign a contract. Currently they're offering installed panels at $3.30 a watt. A 9 or 10kw array would likely meet all our electrical power needs. Also at the meeting were lenders who will finance the net cost (less 5% down) for 15 years at 6.5%.

In General questions | Asked By Patrick McCombe | Jan 24 14
1 Answer

Ducts inside?

Has anyone done or seen soffit or chase retrofit inside home envelope from flex duct in the attic? In other words, move ducts indoors.

I want to get rid of my 20-year-old falling-apart money-hungry flex ducts that are in the attic. Read that it is more efficient inside. My Jim Walter home is more like a double wide mobile home about 1200 sq ft single story ranch, raised foundation crawl space, no basement, central air with air handler inside.

In Energy efficiency and durability | Asked By Valerie Morgan | Feb 25 14
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