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1 Answer

How do you insulate an open web truss cathedral ceiling? (The spaces in the web being the issue.)

the web space is 15 inches

In Green products and materials | Asked By dan grant | Apr 13 13
21 Answers

R47 Wall and R 66 Roof – “Mind the Gap - the Almost Perfect Wall”

I would really appreciate some feedback from the group on my version of the “Almost Perfect Wall” for my home in Southeastern Michigan (Climate Zone 5)


One of my big questions is…what to tape? The Rigid Insulation, the House Wrap...the Plywood

Wall Components from the Inside out:
1/2” Gyp
Dense Pack Cellulose Cavity Insulation (5.5@3.8=R21)
2x6 Wall Studs @ 16” O.C.
1/2” Plywood Sheathing
Crinkled House Wrap
2 Layers of 2” Polyiso Rigid Insulation (4@6.5=R26)

In Energy efficiency and durability | Asked By Howard Road | Apr 2 13
6 Answers

Roxul or polyisocyanurate?

I am putting together the design/spec for a deep energy retrofit of a 60's bungalow in Calgary, Alberta. I will be applying an insulation product to the exterior of the sheathing to eliminate as many thermal bridges as possible.

As a big part of the retrofits intentions are for environmental reasons, I want to use as benign materials as is possible and fiscally reasonable. With regard to exterior insulation I am debating on either 4" Roxul RockBoard 80 (R16.4) or 4" of polyisocyanurate board (R24).

In Green building techniques | Asked By David Richardson | Apr 9 13
3 Answers

Are there any government tax credits for solar panels?

Are there any programs to defer the cost to install solar panels on a residential house in Mississippi?

In General questions | Asked By margaret kennedy | Apr 12 13
2 Answers

What is the recommended thickness of a vapor barrier under a 18" raised house in southern Miss.?

What is the reccomended thickness of a vapor barrier under a 18 inch raised house in southern Mississipi?

In General questions | Asked By margaret kennedy | Apr 12 13
1 Answer

What are the advantages and disadvantages of flash and batt insulation?

What are the advantages and disadvantages of flash and batt insulation in south Mississippi?

In Energy efficiency and durability | Asked By margaret kennedy | Apr 12 13
2 Answers

Outsulation, Persist Walls and attached garages

Me and my fiance recently put an offer in on our first home. It is a small modular rectangular rancher built in 1991 and quoted to be an "energy star" model. Full basement (original owner who was there during construction confirmed no sub slab insulation or exterior wall insulation). Unfortunately it is not oriented due south (it is roughly 30 degrees off of due south) but after looking for about a year it was the best compromise we could find in our price range, lot size, location and school system.

In Green building techniques | Asked By Lance Carsillo | Apr 11 13
2 Answers

Do any of the double-stud wall details enclose air conditioned spaces?

I see that you now have double stud wall details in your detail library. These details are probably from projects in zone 7A, so a poly vapor barrier may be used, but are any of these buildings air conditioned? If so, how does that affect the use of the vapor barrier in this zone?

In Energy efficiency and durability | Asked By Stephen Martinson | Mar 13 13
7 Answers

Options for handling a porch beam penetration into a wall cavity

Looking for options as to how best handle a front porch beam penetration into the exterior wall cavity to rest on two 2x4's for support. The basic wall construction is 1.5" of Huber's Zip R6.6 sheathing, 2x4 studs & R15 blown insulation. Location is zone 5 (central OH). The porch beam was installed through the wall cavity and is now resting at the end of the 2x4's it's supported by ... essentially no room for insulation at present at the end of it as it extends into the wall of a Study.

In Energy efficiency and durability | Asked By Milan Jurich | Apr 8 13
7 Answers

I need assistance in choosing a spray foam insulation for my roof rafters

I have a house that was built 1904. The upstairs has no insulation between the room & the shingles. The roof rafters are true 2"x 4"'s with plywood & shingles above that. The height of the room at the peak is 6 foot, so no room to add any insulation below the rafters.

Spray foam appears to be my only choice, 4" of foam will be better than none at all. We live in the NE corner of Alberta, in the Village of Vilna, 60 miles NE of the City of Edmonton. Winters get down to -40 degrees.

In Energy efficiency and durability | Asked By Ron Farmer | Apr 9 13
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