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1 Answer

Rigid polyiso in side attics?

As a spray foam alternative, I'm considering using continuous rigid foam along the 32ft long x 7ft slope in my side attic and just spray foaming in the lower joist bays and places where taping is difficult. The attics are about as simple as can be with no dormers or other obstructions. I will need 8" of polyiso to meet my disired R-value (R-48), while keeping the 2x4 rafter bays wide open for ventilation. There are also HVAC ducts and plumbing in the attic, which is why I'd like to convert it conditioned space.

In Green building techniques | Asked By Ryan Griffin | Nov 22 14
1 Answer

High R-value CMU?

They are claiming R 19.5 on an 8 inch CMU. I guess they are adding up inches of EPS and not deducting for the LARGE thermal bridging effects:

http://www.emcoblock.com/products/block/omni-block-high-r-block.php

I'm not crazy am I? This is outlandishism in terms of r value performance?

In Energy efficiency and durability | Asked By leo kloop | Nov 22 14
12 Answers

Polyiso on interior

Martin/Dana

Living in the Bellingham area north of Seattle it can get cold. The house was heated by propane, it was a cost that was hard to get hold of especially with some of the design of the house. (high ceiling)

I set out to improve the insulation of the home taking bits and pieces off the internet as to the techniques available these days.

I am a bit "OCD" now that the living room is for the most part done "I have some hidden inward worries". I wonder if I am trapping moisture inside my walls having used the foilfaced polyiso just behind the sheetrock.

In GBA Pro help | Asked By William Lucrisia | Nov 21 14
11 Answers

Insulating an uninsulated Cape-style home (cathedral/knee)

Hi all, new member here; new homeowner too.

In General questions | Asked By Nathan Schulte | Nov 20 14
5 Answers

Proper wall to attach rigid foam to the inside of the wall?

Question: what is the best way to attach rigid foam (foil faced polyiso) board to the inside of a finished wall? Can I just use longer drywall screws to go through the 1" foam and existing drywall? What if I'm going with more than that (say 2 or 3 inches of polyiso)? I'm worried that this method would have a greater tendency to pop the drywall screws out under small impacts like hanging a picture. I'm also worried that the walls will sound hollow or be bouncy when knocking on them. What are the best practices for each thickness of foam?

In Green building techniques | Asked By Ryan Griffin | Nov 17 14
1 Answer

Can rigid foam insulation have an air space between it and rim joist?

I am insulating my rim joists with 2" rigid foam board. Most of the rim joist is bare, and the foam fits along it nicely. Some sill boxes have some small irregularities (vent pipes, plumbing, etc) that I have worked around easily enough.

In General questions | Asked By Susie Derkins | Nov 22 14
2 Answers

Super insulating and soundproofing

I'm curious as to whether anyone has integrated soundproofing techniques into superinsulated walls. As mentioned in other posts, I'm considering adding thickness to my existing walls in the form of rigid foam, without removing current drywall. I hear foam is not the best for sound, although at least the 3/4" airspace and second layer of drywall will help. I'm curious if anyone else has explored trying to get the best of both worlds, R-value and sound reduction, while keeping thickness to a minimum.

In Green building techniques | Asked By Ryan Griffin | Nov 22 14
4 Answers

Has anyone found a window that meets passive house standards and also carries an ASTM impact rating for the 110 mph zone?

So far the only thing I find that's close is from Dynamic.

In Green products and materials | Asked By Carole Hunter | Nov 20 14
6 Answers

Home energy monitoring programs

I am building a net zero energy home to Passive House standards in the Seattle area. In addition to having it be as efficient as possible, my goals were to use renewable materials (no foam), eliminate thermal bridging. have a protected air-barrier and to keep the OSB warm. I'm using dense packed cellulose in the R-50 walls and R-85 roof (cathedral ceiling with parallel chord trusses). The wall assembly is a double stud system with an inner 2x6 load bearing wall and an outer 2x4 wall.

In General questions | Asked By Gerald Blycker | Nov 21 14
2 Answers

Blower door testing by floor or room?

Hello,

In PassivHaus | Asked By Ryan Griffin | Nov 21 14
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