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5 Answers

Previous code for unvented cathederal ceiling insulation

Hey All,

Just curious if anyone knows the previous insulation codes for a low pitched, unvented cathederal ceiling.

My home was built in the 60s and I am finally getting around to insulating and finishing the garage with the above described roof. I know current code is r49 with at least r20 of spray foam for dew point and that's my only option. I just don't see how the rest of my house is all still ok since it was built/insulated way before spray foam existing. Now if I want to just fill the garage bags with roxul or cellulose I hear my roof will mold and collapse.

Asked By Steve Gabrielidi | Nov 25 15
48 Answers

Buyer education versus a good code and intensive enforcement of it

This is kind of a general question. I'm seeing more and more issues coming up on GBA questions and answers regarding shoddy construction that homeowners are having to deal with. I read it recently in Peter L's description of some builders in the Phoenix area. This is most concerning when one is having a new home built, or purchasing a previously built new home, and it has subpar construction.

Asked By Eric Habegger | Jul 21 15
3 Answers

Roof insulation

The building: 1968 5-plex in Portland, Oregon.
The old roof: tar + gravel, flat.
The new(er) roof: asphalt rolls laid over a slightly built-up frame over the old flat roof. Probably as much as 6-8" between the newer roof sheathing and the old abandoned roof.
The joists: 2x8, 16" O.C., insulated with paper-faced fiberglass (a long time ago, it would appear). Though the walls are to the studs, we have not planned to demo the ceiling, so we're hoping to leave the batts in place.

Asked By jonathan nagar | Oct 26 15
2 Answers

Health risk of 2x6 wall with 1" exterior rigid foam, cavity filled, and inteior stud wall strapped with poly membrane?

Hello ... I have a quick question on the practicality of the health risk posed by trapping moisture within a 2x6 stud wall cavity. There were condominiums built in our area, 1 which I happened to live in for a few months, that had the exterior walls built in the fashion of having brick (lower units) / stucco (upper units) followed by 1" of Poly Iso foil faced rigid foam on the exterior with the cavity filled with fiberglass batt-insulation and then they ran plastic sheeting on the interior of this stud wall.

Asked By Jon R | Oct 30 15
1 Answer

I have always heard you could not use pressure-treated lumber on the interior of a house

What about bottom plates that come in contact with concrete in a basement?

Asked By Emmett Sewell | Oct 27 15
8 Answers

What are your thoughts about a small kitchen without a range?

The kitchen in my condo is 82" x 69" so I planned to have a Wolf countertop oven instead of a range and a hood. The city building permit office approved the plan but a prospective buyer's lender insists the kitchen needs a range. Any experience with small kitchens without ranges?

Asked By Mary Schwaba | Oct 22 15
5 Answers

How do you assess flash-and-batt installations?

We have begun to see more Builders and Insulators use flash and batt installation and I am not sure how to assess the R-value of the installation and if the installation actually meets the intent of code and programs. Let me make the case… First premise it that RESNET grade one installation is equivalent to meeting the intent of the code as the code only say that insulation must be installed in accordance with manufacture instructions.

Asked By Robby Schwarz | Oct 11 15
4 Answers

Venting an existing flat roof

We have a row house in Chicago. The drawing indicate (it seems it was built as drawn) that we have a 1/4" per foot modified bitumen roof. We don't have soffits or ridges (just parapets on three sides and a gutter along the back). The roof structure is min 16" wood roof trusses at the low gutter end and they get bigger at the front. We have R49 Green Fiber blown in cellulose insulation in the trusses. There is no vapor barrier (as the insulation suggested) and there is two layers of 5/8" drywall at the ceiling. We have mushroom vents at 1 sq. ft. of net free area for every 300 sq. ft.

Asked By Trisha Megan | Oct 8 15
11 Answers

Exterior siding layers?

Hello all, I have a quick siding question.

When we spray foamed my shop with close cell spray foam we sprayed against the tyvek(housewrap). It was only one layer. It seemed like the best option we had at the time as I knew I would down the road drop the T-111 osb finished siding and replace it with plywood siding and housewrap and then a cement overlay (making faux stone work out of the cement)

Asked By Max Anthony | Sep 26 15
5 Answers

Discussion of unvented foam-free roof assembly

I've had this article stuck in my to-read list for a while, and just got around to it. I searched to see if it had already been discussed on GBA and didn't see anything, please point me in the right direction if it's already been covered:

This assembly was put together by David Posluszny, whose house in MA has been discussed in depth. This assembly is a bit different, as it's installed in an existing attic and doesn't include any changes to any roof layer from the sheathing out.

Asked By Sam S | Sep 5 15
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