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

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4 Answers
Cost of a corrugated roof for a 1200 s.f. house?

I'm working with a design-build firm in Oregon and my builder doesn't want to use corrugated metal for the roof, saying it's way more expensive than regular standard roofing material. Is this true?

In Green products and materials | Asked By s. bonte | Jun 5 13
4 Answers
Where can I find a national average for general contractor prices?

Where can I find a national average for general contractor prices on misc. jobs -- e.g., roofing, framing, flooring, and plumbing?

I need a price list for a range of general contractor jobs... such as carpentry, plumbing, electrical, heating....etc. Is there a website that shows a national average for prices to be paid to general contractors?

Thanks!

In General questions | Asked By John Poulette | Jun 4 13
5 Answers
Recommend a very quiet, low-CFM exhaust fan?

I need the quietest, continuous-run bath fan available for a small building. It's a 400-square-foot, 4500-cubic-foot space to be used as a painting studio and occasional guest quarters. One bath, no kitchen. I'm expecting it to be 1-2 ACH50.

The plan is to install the fan in the bathroom ceiling, although there is a very small concealed space that could house an inline fan. I don't think this project needs a HRV, and in any case there isn't anywhere to install the ductwork for one.

In Mechanicals | Asked By David Meiland | Jun 16 13
17 Answers
Does this roof assembly work?

I am building a house in upstate NY. I am about to finish framing and have begun to doubt my unvented roof design. Specifically whether I need to add a path for drying the layer of plywood that will be beneath my metal roofing. This is the sequence from the bottom up: 2 x12 rafters filled with cellulose, layer of 5/8" ply, 3" of polyiso foam board, 5/8" ply completely covered with ice and water membrane, metal roofing. It is a pitch of 1" per foot.
Should there be an air space between the foam and the ply above? My air barrier was to be the ice and water membrane!

In Energy efficiency and durability | Asked By Christopher Regan | Jun 11 13
1 Answer
REMOTE: Drainage cavity between insulation and exterior membrane?

The REMOTE Manual does not indicate that a drainage cavity is needed between the rigid insulation and the exterior membrane. Lstiburek's "The Perfect Wall" article, which is a similar assembly (or the same?) does not suggest this either. Has anything surfaced in the last few years to suggest a cavity is needed between these layers?

I'm in zone 4A, planning to use foil-faced polyiso. I have not selected the membrane yet.

In Energy efficiency and durability | Asked By Matthew Luedders | Jun 15 13
8 Answers
How important is thickness of window glass?

Greetings,

We are embarking on replacement of all of the windows in our home from the original single pane windows ('97 construction) to something more energy efficient, as well as meeting the storm codes for South FL. Although we've found a lot of valuable information online, something that I've yet to come across is what difference does it make to go with 5/16" glass, vs. 7/16."

Some of the estimators who have come to our home seem to really be pushing the 7/16" as 'better,' while others are telling us that 5/16" will work just fine. We're looking to install Lo-E insulated windows.

In General questions | Asked By Luis Rosario | Jun 12 13
8 Answers
Best way to supply fresh air to finished basement?

My apologies in advance for the length, but since I may not be able to get back here for a few days I tried to anticipate questions and provide sufficient detail.

In General questions | Asked By Anne Biles | Jun 7 13
16 Answers
Suggestions on the best place to sell used EPS foam insulation?

Currently a roofing company I work with is removing two layers of 3.5" EPS foam from a project in preparation for reroof. There will be approximately 2,000 pieces of 4'x4' foam with minimal damage and I imagine are completely reusable. I appreciate the collective intelligence of this community greatly. At the risk of sounding like a newb . Does anyone have any suggestions of where to sell this material or other used materials? The project is in Bozeman MT. Far from large markets.

In Green products and materials | Asked By martin fahrney | Jun 6 13
7 Answers
Weeping tile (French drain) access or cleanout?

I am installing a drainage mat in a small section around my foundation. While i am installing it, I am wondering if there is any real word advantage of creating a "clean out" or or inspection pipe that leads to the surface.

thanks

In General questions | Asked By cory shwartz | Jun 9 13
3 Answers
Does the soil under an insulated slab warm up?

The point of this question is to see if you really need R20 under a slab or if R10 is good enough.

The water from the street in Denver comes in at 45F in the winter, and 65F in the summer. That tells me the average ground temp is 55F, since that water has traveled many miles at a four foot depth.

From Wikipedia, the ground temperature remains very constant year round below 20 feet.

In Energy efficiency and durability | Asked By Kevin Dickson, MSME | Jun 11 13
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