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13 Answers

I am overwhelmed with the wall cavity options and need advice

After researching for the last few months on this website, buildingscience.com, and PHIUS.org I am just overwhelmed...buy maybe under informed. I am an owner/builder (former construction project manager...mainly responsible for foundation and electric work then) and this will be my second house. Most of the case studies and articles I have read are about homes in climate zones far more extreme than what we typically have in TN.

Asked By Andrew Bennett | Mar 4 15
1 Answer

Insulation Retrofit for Radiant Floor Heat

I've searched this site and found a lot of useful information but no clear consensus on what is the "best" method for retrofitting insulation in radiant floors. The situation is exposed hydronic tubing stapled up to the subfloor with no heat transfer plate. The joist bays are relatively accessible from the insulated basement and crawl spaces. Climate Zone 6.

Asked By Brent Mellen | Mar 6 15
3 Answers

Spray foam optimal or does another solution exist?

Asked By Todd Munson | Mar 6 15
2 Answers

Insulated slab details for zone 7 walkout

My build is in Kenora Onrtario Canada (zone 7). The basement is a walkout; I need to incorporate a sewage lift station under the floor to pump (shower/toilet/sink and washing machine) water up to my septic
I need to know how to detail the insulation and poly layer under the concrete.
Do I insulate the sides and bottom of the hole the tank (110 gallon) goes into; if so do the joints have to be taped like building an foam box; I can't have the sewage freezing in the tank! Is that even a concern?

Asked By tim brown | Mar 5 15
19 Answers

Basement is too cold, need help in insulation

Hi,
I live on the border or CT and MA. My basement is around 47 degrees. I have my basement roof insulated with R30 batt insulation. When I measured the temperature of my basement walls, above grade part is coming around 35-40 degrees and below grade is about 40-45 degrees, my basement floor is around 45-50 degrees. I put durashield paint on the basement walls to prevent from moisture ( I did not have too much moisture but I still wanted to avoid any future issues), similarly I painted my floor with two part epoxy.

Asked By Amit Jindal | Feb 16 15
11 Answers

Why is it so trendy to hate on radiant in-floor heat?

I recently built a 2000 square foot house in climate zone 7. The building is two stories on a slab heated by a Navien 240a combination boiler. There is no heat source on the second story, and the simple system has only one zone, which is all it needs because all the rooms in the house stay at the same temperature--maybe it's a few degrees cooler in the upstairs bedrooms if the doors are shut for 24 hours or more. I spent just over five grand on the heating system--installed--although I got a tankless water heater in the process, so the real cost was more like $3500. How is that overkill?

Asked By Josh Jipson | Mar 1 15
2 Answers

PERSIST - Vapor-open or vapor-closed insulation and WRB?

So I just got back from Building Energy 15' - what a great conference! I had a few conversations about various vapor barriers, insulation and how each works with the PERSIST technique. I wanted your feedback though......

Asked By brad hardie | Mar 6 15
2 Answers

Membrain in walls, poly in attic. OK or not?

I join hundreds of others in trying to wrap my head around the nuances of vapor retarders.

In this thread in comment #32 Martin notes that ceiling poly is unlikely to cause much trouble and then in comment #34 he observes that another person should use Membrain in their walls.

Is there ever a need for Membrain in the ceiling or can cheaper poly always be used?

One other question.

Poly in walls should be on the warm side, Martin quoted the following from the same article:

Asked By Alex House | Mar 6 15
3 Answers

Who remembers Fred Lugano?

Fred over a break time pushed for air sealing years before the rest of us and passive house. Other smart folks missng now... Michael Chandler, and Robert Riversong... Many more right....

Asked By aj builder, Upstate NY Zone 6a | Mar 6 15
6 Answers

Recommended taping of plywood and foam layers

I am building a small casita (500 sq. ft.) in Northern California in a mild climate with hot summers. My wall framing is 2x4 w/ 3/8 continuous plywood shear (also insulated w/ R-13 fiberglass batt insul.), which I will cover with two layers of 1/1/2" Polyiso (Firestone) insulation (has fiberglass reinforced face). I will cover everything with Tyvek housewrap and fasten 1x4 battens creating a rainscreen, and attach lath and plaster as an exterior finish to the battens.

Asked By Dan Burgoyne | Mar 5 15
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