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6 Answers

Do I need to use R10 minimum on the roof deck in climate zone 4C in all cases?

I am detailing a low slope unvented roof. I will be using spray foam & then batt insulation to total R38 under the roof deck in Climate zone 4C. I could meet code just with that but would like to use rigid EPS board, R6, on top of the roof deck to prevent thermal bridging. This introduces a third insulation that is not covered in the code
- Do I need to use R10 to meet the minimum above deck value? Does this rule still apply since I'm using spray foam directly below the deck?
Thanks, Andy

Asked By user-7003242 | Jun 22 18
7 Answers

Building code requirements for stacked window headers, bracing, and stucco over foam

We are building in climate zone 5 and the county currently enforces the 2009 IBC & IRC.

We prepared a list of questions for our building inspector, some of which are location specific, but since we have gotten no response we figured some of this is probably common knowledge.

1. Do non-load bearing walls require structural headers?
2. Can vertically stacked windows of the same width share a header and king studs?

Asked By Zane Bridgers | Jun 17 18
9 Answers

Is there any way around putting a heat source in every bedroom?

I was speaking with an HVAC guy in my area today who reminded me that code says we have to have a heat source in every bedroom. We're planning on putting a single head ductless minisplit in our 1450 sf high performance home (to be built next year). Are there other exceptions/solutions out there, or do I just stick a Cadet heater in every bedroom and disconnect them after the inspector checks it off his list?

Asked By Alyssa Hoyt | Feb 4 16
4 Answers

Insulation in a non-vented roof assembly

I am building a flat roof home that we are using TPO roof on that the roofer will need a minimum of 1" polyiso for an underlayment. I plan to spray the underside of the roof sheathing and up the vertical side of the raised heel truss with closed cell foam for air seal. So my question is, to protect the roof sheathing from condensation is it better to use the 1" of Polyiso and 2" of closed cell or 2 of poly and 1 of closed cell?
I am in climate zone 5.

Asked By Kelly Coons | May 27 18
1 Answer

Does the roof sheathing side in the attic space have to be insulated?

in some rooms in the upper levels there is attic space with an access door. I realize that the walls which are against the liveable space have to be insulated, but does the side with the roof sheathing have to be insulated? This is the side where the roof shingles are attached.

Asked By C D | May 19 18
4 Answers

Roof ventilation for an L-Shaped (Plan) house with a shed roof

Climate: 4C (near Seattle)

I'm working on a 1-story home with an L-Shaped plan that will have a shed roof (low side of roof at the interior corner of the plan).
The roof will be constructed with trusses where one wing of the house would have a conventional attic but the other wing would have parallel chord trusses (~18" deep).
There will be a continuous soffit vent at the high and low sides of the roof for ventilation.

Asked By Daniel Stewart | May 13 18
1 Answer

Can I frame over blanket insulation and vaper barrier in the basement and get proper Fire Blocking?

I would like to leave the insulation blanket and vaper barrier in place when I frame the walls in my basement. Is it permissible to frame out from the insulation and then place the horizontal fire blocking every 10 feet by just compressing the insulation with 2x lumber against the concrete?

Asked By R. S2 | May 10 18
3 Answers

Vapor barrier for garage roof without drywall?

I recently purchased a house that has an attached unconditioned garage with an uninsulated roof. The garage gets 15 to 20F hotter than the exterior temperature in the summer. Also the roof originally had skip sheathing, and plywood was added over that when the roof was redone at some point. Tar paper was left between the skip sheathing and plywood, so that is currently exposed to the garage interior. The garage stinks of tar in the summer when the roof heats up. I'm located in Portland Oregon Zone 4c

Asked By Peter274 | May 2 18
6 Answers

Has anyone used Airfoil electrical boxes in Ontario, Canada?

Will they meet code?

Asked By User-7049195 | Apr 25 18
2 Answers

Is Rmax Thermasheath-XP an acceptable alternative to Dow Thermax?

I intended on using Dow Thermax for an exposed basement application in a residential setting.

I thought there were no alternatives without using an ignition barrier (drywall) but recently came across Rmax Thermasheath-XP. For my purposes, I believe this would be a more affordable option.

Does anyone have any experience with this product? It seems to have similar properties to Dow Thermax. Does Dow Thermax have any documented advantages?


Asked By NatePa | Apr 19 18
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