Q&A: A Forum for Green Building Experts and Beginners

Q & A Instructions

[Click map to enlarge]

The GBAGreenBuildingAdvisor.com web site has a wealth of articles on a wide variety of construction topics. Before posting your question, you may want to check out the articles on this page: How To Do Everything. You just might discover an article there that provides the information you seek.

Please register for a free account or sign in to ask and answer green building questions.

If you want to post a question, the usual rules of courtesy apply:
1. Be nice.
2. If you can't be nice, be polite.
3. If you can't be nice or polite — well, please be brief.

To attach a photo or illustration: Under the box labeled “More explanation,” look for the words “File attachments.” Click that, and you should be able to attach a photo.

Thanks for joining the conversation!

3 Answers

Are there any builders, architects, engineers, or homeowners interested in industrial hemp building?

Energy and bio-friendly materials significantly solve many issues I see here, and despite code/cost and other issues, it is a solution many are embracing...

Hempcrete, hemp fiber insulation, hemp particle board, carpets, furniture are all available and becoming more mainstream alternatives with immense positive experiences. Anybody have experiences or interest in this?

In Energy efficiency and durability | Asked By Kristin Steen | Jun 16 15
4 Answers

Float deck on Deck Blocks in the Northeast?

Year into owning our house we are discovering more and more that placing deck furniture on grass is not sustainable practice. So I am looking to build something that covers 12X16 area and isn't much taller off the ground than say 6"-12". Definitely not attaching it to the house or I am going to be in permit territory, which makes the taxman very happy in my town.

In General questions | Asked By Apollo S | Jun 16 15
5 Answers

Heat Recovery Ventilation

Being a retired architect, I did not learn about heat recovery ventilators (HRV) until 5 years ago. The first installation I tried on a client’s house was three years ago. Planning to install more, I asked my former client about his experience with the unit. He told me it didn’t work very well, since in the winter it blew cold air into his bedroom. So, when I called the manufacturer’s tech assistance number yesterday, they asked about my experience with their product. I said fine, except for the problem with cold air.

In Energy efficiency and durability | Asked By william mccullam | Jun 9 15
1 Answer

Do these calculations seem reasonable?

I created an excel heat loss model for a proposed house design to help me select what steps beyond code compliance will have the most impact. I would appreciate any comments that more experienced people might have on my results. The house is about 2300 square feet above grade in climate zone 5 (about 100 miles from the zone 6 border). The second floor is about 1/3 the size of the first floor. The baseline code compliant model uses the following assumptions:
• 2x6 walls, 16 o.c., cellulose in cavity
• Attic cellulose R = 38
• Basement R = 12
• Windows U = 0.35
• ACF50 = 3

In Plans Review | Asked By Reid Baldwin | Jun 16 15
14 Answers

Continuous Air Barrier at Ceiling with a Raised Heel Truss

Just came across this article referencing Joe Lstiburek speaking about creating a continuous air barrier:

In Energy efficiency and durability | Asked By Brian W | Jun 11 15
15 Answers

What would a Class I, II, and III energy code look like ?

We are building a new house and struggling massively on the energy side. Architects and builders that we like don't know much about energy efficiency (nor IAQ, Low VOC, etc.) and those that know energy efficiency largely build very contemporary styles. We may be faced with trying to marry the two which could be prohibitively expensive unless we can get them to fall in love with each other before work begins.

In Energy efficiency and durability | Asked By W Ramsay | Jun 11 15
1 Answer

Peel-and-stick selection

Are there any features to look for when selecting a peel and stick membrane for a PERSIST style wall retrofit?

I’m planning to remove the siding from a section of my house and insulate with rigid foam on the exterior. My plan is to remove everything back to the board sheathing (tongue and groove ¾” material) and apply a peel and stick sheet membrane over the boards, then 2 layers of EPS foam and then furring strips.

In General questions | Asked By Mark Fredericks | Jun 15 15
2 Answers

Where to recycle drywall scraps from a new build in San Diego, CA?

My family owns a hauling company and we are new to the construction sites. We have a large job coming up in which we are hauling away only drywall. I'm always interested in recycling materials we haul in order to keep costs down and to keep items out of the landfill. When I started looking into recycling scrap drywall I found many obstacles. Is there any place to take cut pieces of new drywall in southern California (San Diego)?

Thank you for your time, Jill

In General questions | Asked By Nancy Fortune | Jun 15 15
3 Answers

Insulated basement slab vapor barrier location - above or below the under-slab insulation?

We are planning the prep work for a basement radiant slab in our house addition. The proposed material stackup from bottom to top is:

1. Compacted gravel fill
2. 3" XPS rigid foam under slab (also 2" of vertical insulation isolating slab edge from basement wall)
3. Poly vapor barrier
4. 4" slab with welded wire mesh reinforcement and PEX hydronic tubing

Everything I read on the Building Science Corporation web site says to put the vapor barrier ABOVE the XPS rigid foam. (between slab and rigid foam).

In Energy efficiency and durability | Asked By Michael Tuso | Jun 15 15
5 Answers

Construction Waste

I often see proponents of different construction methods, like pre-fabrication or SIPS, using the efficiency and reduction of waste as part of the appeal. Can someone explain the rationale behind that claim?
All of the materials I buy, like dimension lumber, sheet goods, pipes, wire etc, are manufactured in certain sizes. Whether I cut them to length on the site or in a shop doesn't alter that. Where are the efficiencies?

In General questions | Asked By Malcolm Taylor | Jun 12 15
Register for a free account and join the conversation

Get a free account and join the conversation!
Become a GBA PRO!