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4 Answers

Spray foam and electrical wiring

I recently had a conversation with a couple members of my family who are both electricians. In their continuing education class the instructor mentioned that the National Electric Code is monitoring the use of field applied spray foam and electrical wiring that becomes imbedded in the process. There have been failures in the wiring because of the heat that can build up in the covered wires, usually the problem is with constant and motor loads that operate at a higher ampacity.

Asked By Randy Williams | Mar 18 18
7 Answers

DIY air sealing equipment

Other than a blower door, which is impractical for this application, what specifc products do you recommend for a homeowner interested in air sealing? What is the best homeowner-grade thermal imager (if there is one), smoke pencil, etc?

Our moderate retrofit reduced a very leaky, large house from 7330cfm to approx 5000cfm, and I want to keep going.

Thank you.

Asked By Emerson | Mar 13 18
15 Answers

Another flat roof question

We have several hundred sq. ft. of unvented flat EPDM roof above a single story addition. The rafters are 2x8. We recently cut access and found 2-3" of very old fiberglass batts in the rafter bays - a total roof insulation of R11. When the roof needs to be replaced in >10 years, we will install external foam sheathing.

In the interim, what is the best way to increase R value without creating a moisture problem? And if every approach has risks, what are they?

Thank you.

Asked By Emerson | Feb 7 18
0 Answers

Thickness of Closed Cell Insulation in 2x4 Walls

I've built a 200 sq ft structure (tiny house on wheels, not inspected) with 2x4 walls and 2x6 rafters. I'm ready to insulate and have been planning on using closed cell spray foam for the whole thing to avoid moisture issues in the unvented cathedral ceiling. (I would love to use Roxul instead if it were an option). I don't have any can lights or skylights in the ceiling and only one penetration for the range hood.

My climate is 5A.

Asked By Mike Spooner | Mar 18 18
3 Answers

To Spray foam or not?

I am trying to decide whether to spray foam my house which is currently down to the studs. I am in climate zone 2 so it is hot and humid most of the year. The house currently was built to have a vented attic. The house is about 3,000 square feet and is one story. I have a asphalt roof shingles that I had installed last summer. My HVAC equipment and water heater are in a mechanical room separated from the living space by walls and with a louvered door to the outside.

Asked By Kasey Doggett | Mar 18 18
4 Answers

Fixing Unvented Cathedral Ceiling Insulation


Asked By RobJ13 | Mar 17 18
15 Answers

ZIP, AdvanTech, OSB, and Plywood.

ZIP, AdvanTech, OSB, and Plywood
What are people’s preferences/experiences when it comes to these products in the two following locations?

Roof Sheathing – Vented attic, with metal standing seam over top. Also what underlayment would you use with each?

Wall Sheathing- Inside to out lay-up is ½” drywall (hopefully fairly airtight) (possibly a membrane required by building inspector), 2”x4” studs, ½”sheathing taped (3M) (air barrier), 2 layers of 3” used fiberglass faced polyiso (6” total) Tyvek (WRB), horizontal ¾” furring strips, vinyl board batten siding.

Asked By Dave B | Mar 14 18
20 Answers

New Home Construction, Slow Bids, Confused Builders

I'm at the southern edge of Climate Zone 5A and want to build a better than code house, what some might call a "pretty good" house, one that includes the most cost effective of the concepts described in Martin Holladay's "Musings of an Energy Nerd" book. One builder I spoke with discouraged having a continuous layer of insulation on the outside of the walls, or on the basement floor stating that such improvements weren't needed and were too expensive to be worthwhile.

Asked By Illinois Prairie | Mar 14 18
0 Answers

Wide gap between mudsill and foundation

Hi all,

I am in the process of air sealing and insulating the rim joist area in my crawl space. I've already caulked in each of the bays and am about it install XPS and seal around with canned spray foam.

While crawling around I noticed that the mudsill is anywhere between 3/4" to 1 1/4" off of the top of the foundation wall. There are shims spaced out all around, some of which are degrading.

The main section of the house (with a full basement) was built in 1976 and the addition with the crawl space I am in was probably done sometime in the 80s. We moved in about 3 years ago.

Asked By user-7039735 | Mar 18 18
12 Answers

Should I vent a cathedral truss with a metal roof and foam insulation?

Using 2 layers of 2 “ Poly foam under the roof strapping then 2” air space and 1 more 2” Poly going across the top chord of truss to eliminate thermal bridging.

Asked By User-7034059 | Mar 10 18
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