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3 Answers

Spray foam fire-retardant painting

Recently I had my cellar a crawl space professionally sprayed with closed cell foam. The company was supposed to return to spray on fire-retardant paint. The crawl space is difficult to work in and they company has offered me several hundred dollars discount to leave it unpainted. They tell me that there is actually no requirement for the fire retardant paint in a crawl space, and that because there is no source of ignition in the crawl space, so it is safe. There is a living space directly above the crawl space.

Asked By JoshuaB | Mar 17 18
6 Answers

Fixing Unvented Cathedral Ceiling Insulation


Asked By RobJ13 | Mar 17 18
2 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
22 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
10 Answers

Exterior Detail Between Poured Porch/Cold Cellar and Main Floor?

CZ6A, Ottawa ON

Having trouble figuring out how to handle exterior wall details at the front entrance where we have a poured slab over a cold cellar meeting up with the house at the front door. The slab will only be an inch or two below the front door (no distinct step, as flush as possible), but the main floor joists will need to sit on the foundation ledge 8" or so below the slab level.

Asked By Lance Peters | Mar 16 18
10 Answers

How to Reduce High Energy Costs for Ductless Minisplits

Hello Martin,

I have the Mitsubishi H2i heat pumps as my primary heat source at my south east MA home. Seven indoor units [9 and 12K's] and two outdoor units [MXZ-3C30NAHZ, MXZ-4C36NAHZ]. The 2,400sqft 1980 contemporary style house has lots of [1st gen. Anderson double glazing and Pella single with interior "storm" panels] windows. The Pella's are actually [relative] better thermal performers. The wall insulation is typical of that generation, poor to fair. The attic has about 20" blown in insulation.

Asked By kazirode | Mar 16 18
5 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
2 Answers

Framed floor over concrete slab

I'm working on building a new home near Seattle (4C) that will be, for the most, a concrete slab on grade finish floor. In the bedrooms, though, I'd like to install carpet and I'm trying to come up with the best assembly to do so.

The slab will have 2-4" of rigid insulation (depending on budget) and a vapor barrier under the slab.

I was thinking of laying (non-pt) 2x4s on edge @ 24" o.c. with a layer of 3/4" plywood over that, then installing the carpet on the plywood.

Asked By Daniel Stewart | Mar 18 18
5 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
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