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6 Answers

Insulating a cathedral ceiling with self-adhesive roofing membrane installed

We are building a 640 sq ft cabin in CZ6. At the last minute we found a metal roof rated for down to a 1:12 pitch and made the change to a 2:12 pitch.

With that change to a flatter pitch came a recommendation from the roofing supplier to cover the roof sheathing with a self adhesive "Ice and Water Shield" type product.

So our roof (all complete) from outside to in:

24 gauge metal roof.

In GBA Pro help | Asked By Chris Harper | Sep 22 16
2 Answers

Temperature adjustment / offset on Mitsubishi minisplit

I installed my MSZ-FH12NA two months ago and the unit is performing very well and I am not experiencing the short-cycling issue that others have, but the unit seems to consistently cool (haven't used heating mode yet) past the set temp on the remote by 4-5 degrees. (If I want it to cool to 70, I have to set the remote at ~74.) Does anyone know if there is a way to offset/adjust the remote control temperature to accurately reflect the actual room temperature?

In Mechanicals | Asked By Adam Emter | Sep 22 16
16 Answers

Spray foam and a vaulted ceiling - working from the top of roof down


Thanks for all the insight on insulating vaulted ceilings - both vented and unvented.

In Green building techniques | Asked By Peter Zwarich | Sep 20 16
7 Answers

Flat roof assembly question

I am replacing the roof on a brick masonry building in NYC within the 5 borough. The building was built in 1910/11. It is a flat roof, about 40 ft long and 25ft. wide. The previous roof (a tar and gravel system) failed and my brother and I removed it, and replaced the damaged roof deck. (a mixture of plywood replaced probably 30-40 yrs ago, and the original t&g boards) with 3/4 OSB. Toward the front 10 foot or so of the building the t&g boards were dry and strong so we left them in place. A little bit of repair to the cornice "box" was necessary.

In GBA Pro help | Asked By Jacob Turetsky | Sep 22 16
1 Answer

Manufactured stone veneer

I know this is not really a green building question, but I am looking for a copy of the MVMA installation instructions, First edition. I have later versions, but was hoping to find the original version. Thanks.

In General questions | Asked By Mark Reinmiller | Sep 22 16
7 Answers

Crawl space ventilation


I am building a raised floor wood construction home in the Monterey Peninsula, CA. The current plan to keep the crawl space dry and ventilated is to put a rat guard, seal off the space, and add a 75+ cfm fan that will have tubing that will draw & supply air from exterior locations. The footprint of the crawl space is about 3700 SF. The height varies from 1.5' - 2'.

My questions are:
Is this a good plan?
What would be good exhaust and supply locations?
Can you recommend a reasonably priced fan for this application?

Much thanks,

In Mechanicals | Asked By Barbara French | Sep 22 16
4 Answers

Converting a flat roof to a pitched roof?

I'm in the process of remodeling my 1950s ranch house. I have a modified bitumen flat roof, which is about 15 years old. The roof is in okay shape right now, however it's sloped incorrectly in about half the roof and has some ponding of a few inches most of the time. There has been some damage to the roof sheathing near the chimney in the past. The rest looks to be in good shape. I'd like to improve the roof and be able to add more insulation to the ceiling as the first part of my renovation. I'd like to get your opinions on the best way to improve the roof.

In General questions | Asked By Betina Chaon | Sep 20 16
7 Answers

Closed-cell foam insulation

We own a century home which over the years has sunk into the ground so there is little or no crawl space. In order to insulate the ground floor, I would like to tear out the old oak tongue and groove flooring, cover the subfloor with a vapor barrier and then fasten 2x4s to the subfloor and use closed cell foam to insulate. Does this sound like a feasible plan?
Chuck Pemberton

In Energy efficiency and durability | Asked By Charles Pemberton | Sep 21 16
13 Answers

Strapping screws: to angle or not to angle?

For 4" of XPS, with a 3/8" airspace and 3/4" plywood strapping, is it sufficient to screw in straight, or do I need to screw in at an angle? I've read where both are "recommended". From my small-scale mockups, screwing straight through seems adequate, but I've never done this before so I don't want to screw it up (sorry :P). The screw pattern I'm using comes from the manufacture's data sheet, and it doesn't specify a screw angle.

In Green building techniques | Asked By John P. | Sep 19 16
2 Answers

Is a reflective surface necessary under radiant floor heating?

I have a situation in a house with a full basement where there is radiant heat in the floor joists of the first floor, accessible from the basement.
There are unfaced fiberglass batts in between the joists under the radiant piping. My business partner thinks we should replace the fiberglass with foil faced foam, but I think it's not necessary.
My partner's rationale is that there needs to be a reflective surface and there is none now.

In Mechanicals | Asked By Josh Engle | Sep 22 16
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