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6 Answers

Wall Assembly-Very Cold Climate Zone 7

I live in northern Maine and will be building a passive solar home. I want to achieve r-50+. Here's a rundown on my proposed wall assembly with three thoughts in mind; 1. high thermal resistance, air tightness, economical as possible. Any ideas/suggestions would be appreciated.

Pine board cladding
Drainage plane
WRB housewrap (ie. Tyvek)
3/4" fiberboard
2x4 outer stud wall (3.5" Roxul insulation) 24" OC
5.5" (or 7.25"?) cavity (Roxul insulation)-chase for electrical
Primary air barrier attached to inner wall (taped OSB treated with liquid vapor barrier)

In PassivHaus | Asked By Matthew Michaud | Dec 29 12
3 Answers

Surface bonding with epoxy


This question is too long. Sorry. Blame it on brain dumps.

I've grown up with farming where many times you don't have what you need, and have to make do. And later in life, I found out I am Autistic, which explains why it is hard to find engineering positions (I have an M.Eng. in materials science and engineering).

In Building Code Questions | Asked By Gordon Haverland | Dec 30 12
0 Answers

Cost Effective Building Options for High Performance Homes

I have observed a number of questions asked in this category and read many GBA articles on the topic. I have also heard of lumber shortages from super storm Sandy and challenges from snow storms and previous ice storms. Here are some ideas from our building project (agreenhearth dot com) and experience:

In Green building techniques | Asked By Patrick Walshe | Dec 31 12
44 Answers

13 reasons why foam fails?

Jetson Green just reprinted some blog content from 475 Home Building Performance, here is the Jetson Green post:
and here is the original from 475:

In Green products and materials | Asked By Adrienne Burt | Dec 18 12
5 Answers

Connecting a bath fan intake to a duct

My bath fan spot is in a bad place. Thinking about connecting it to a duct rather than having it sit directly above the bathroom. Any watch outs in doing this?

In Mechanicals | Asked By stephen edge | Dec 30 12
4 Answers

Raised-frame floor above slab

I understand the importance of super insulating the underside of a slab with large amounts of XPS foam, especially in my very cold climate (northern Maine). I have run across a unique foundation design of a passive house in Falmouth, MA, by architect Steven Baczek (http://www.deapgroup.com/Falmouth_PH.html). It involves insulating ABOVE the slab, essentially leaving the slab out of the conditioned space. His design involves 4" of XPS rigid foam resting on top of the slab, followed by 2x8 16" OC boards spanning the slab, resting on a 2x4 strut. 3/4" T+G subfloor covers the 2x8s.

In GBA Pro help | Asked By Matthew Michaud | Dec 30 12
9 Answers

New Geo or add ETS furnace to existing Geo?

I have an undersized ground source geothermal heat pump for my house. The heat pump is 5 years old and has struggled from year 1 to maintain heat on the days colder than 10 F. Yes, I have tried everything; finally determined that the install contractor (out of business) undersized it for our conditions here in Minnesota. So, do I add an ETS furnace to supplement the inadequacy of the existing heat pump; or, do I purchase the correctly sized system? The costs will be similar. Thanks, J.

In Energy efficiency and durability | Asked By Jaeson Morrison | Sep 1 12
2 Answers

Hot Yoga Studio - Heat and Humidity in the Mountains

I'm doing an interior finish for a hot yoga studio in Edwards, Colorado, 7200 ft in elevation. The1000 sf studio will be heated to 105 degrees and 60% humidity 3 times a day. lasses are at 9:30 am and between 4:00-7:30 pm. The studio will be on the second floor of an older wood framed building. There are tenants on either side and a vaulted ceiling/roof above. The north and south walls are 24' wide with 2x4 framing with plywd. sheathing (building paper?) and t-111 siding with a couple of windows and a door on each side. The shared east and west walls are 40' with drywall and insulation.

In Energy efficiency and durability | Asked By Rick Dominick | Dec 29 12
23 Answers

Incrementally Increasing Insulation in PNW Walls

I am trying to develop a method of increasing the insulation in walls built in the PNW which does not interfere with the normative sequence or techniques of building used in the area. So to be clear this is a "pretty good" approach which doesn't require special trades or materials and can be used in typical houses without significantly increasing the cost, not boutique projects.

In Energy efficiency and durability | Asked By Malcolm Taylor | Dec 23 12
9 Answers

New fastener for applying exterior mineral wool.

We have been working with Fastenmaster in an effort to create a US made screw for applying Mineral Wool that sets in one motion and does not compress the MW. Therefore eliminating the need for "squash blocks" and making application quick while leaving the battens in plane. We have had some success and have a model built for 3" MW. A small production run has been made in the few thousand pcs range.

In Green building techniques | Asked By albert rooks | Dec 20 12
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