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12 Answers

After getting some really helpful advice on here (will link below) for our new construction, we've decided to insulate with Roxul batts that we'll install ourselves. Now that we're looking in to how to properly air seal, it seems like to do it right takes a professional and proper equipment. Is that the case? Should we just be hiring a contractor to do it all (air seal and insulate)? None of the quotes we received for insulation included air-sealing, except for one, which added over 2k to the price. Is this a high, hidden cost of insulation that we're just discovering now?

Asked By Cathy O | Mar 15 13
4 Answers

Hello Everyone.

New here, but have been trying to suck up the knowledge as best as possible. Im sure this is the first of several questions, so forgive me if Im not providing enough/the right info to get things started.

I own an old farmhouse, right on the 5A/6A climate border. Its a foursquare type, with a few additions tacked on the back of it. My questions focus on the main part of the house, since its mostly original everywhere. Build date is circa 1880, built with a mix of new/reclaimed timbers (based on beams in the basement).

Asked By Scott Clark | Mar 18 13
16 Answers


I live in downtown Toronto (Zone 6), Canada. I'm building a brand new addition to an existing 1888 brick house, on a narrow 17' wide lot. I'm interested in getting the best thermal performance (R40) within the thinnest assembly (11" wide) so here is my idea:

From inside to outside -
5/8" GWB
2x4 wood stud framing with
3.25" of high density spray foam (R21)
1/2" plywood
air barrier
5" Roxul Mineral Wool (R20)
1" wood battens or alternately 6" thermally broken z-girts
metal cladding (I am hoping to use a flat seam metal panel of some sort.)

Asked By Jeanne Ng | Mar 12 13
20 Answers

I am planning a small off-grid home and would like to send all surplus energy from the 4.8 kw solar array to a standard electric water heater, probably of 60 or 80 gallon capacity. In effect, it would serve as an additional "battery" once the main battery bank is fully charged. Does anyone have any suggestions or experience on how this might be done in a fairly simple and reliable fashion?

Asked By Peeter Vihvelin | Feb 22 13
3 Answers

Zone 6A NE Pennsylvania. In the design stage of building a home from a restored barn frame. Ceiling will naturally be cathedral the roof system is a complete straight shot from the eves to top ridge. I would like to use recycled poly iso - if there is a better type please suggest. Start with a 1" air space between the 7" of poly iso and sheathing using "sticks". Poly iso would be placed between the 2x12 rafters. Then a 1-2" layer of closed cell spray foam bringing the R value to 49 or above.

Asked By matt bowman | Feb 22 13
10 Answers

This is a follow up to the question we posed here but our problem is a little different. Here are the relevant details of our house:

We're in Zone 5A, building a new house which has already begun construction. We're nearing time for insulation, and realizing that we cannot afford the blown-in cellulose we were planning on using with a Membrane vapor retarder.

Asked By Cathy O | Feb 25 13
41 Answers

I am planning on a home in the Cleveland TN area and want to reduce "conditioning costs" to a minimum (<$50/Mo for all but water).

I want to use cc slabs (4 - 6") on the exterior of the foundation (full hight) but have been personally plagued by termite and carpenter ants in every home I have lived in. Short of soaking everything in dieldrin (hard to come by these days but worked beautifully in MO and has some nasty side effects), what is the current recommendation for stopping the critters outside the foam/concrete interface.

Asked By Ralph Hertlein | Feb 3 13
7 Answers


Asked By Jeff Nelson | Feb 19 13
3 Answers

We are building a 1,600 sq. ft. addition; it is being added to a 1930's farmhouse in the Richmond, VA area (Zone 4, mixed humid). Detail summary: walls are 6 1/2" SIPs, truss roof (see attached file) with partial cathedral ceilings (1 ft. extra heal height for insulation), roof insulation planned is blown-in cellulose (vented attic), conditioned crawl with 2" thermax at interior foundation walls, etc.

Asked By Greg Magnus | Feb 14 13
1 Answer

I am planning to convert our newly built garage into a Tiny House. But, I have come to find that I have a real problem with the off gassing of formaldehyde from the OSB boards. I installed an ERV, the air exchange has been happening for several weeks now, but the fumes are just as troublesome. My next plan is to paint the boards with SafeCoat Safe Seal.

Asked By Diane Hoglund | Feb 13 13
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