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1 Answer

Is it advisable to use nail base insulation panels over a roof insulated with closed cell spray foam?

We are renovating an old railroad station, turning it into a residence and are gearing up to put new roofing on the building. Built in 1888, the building has massive overhangs on all sides and the rafters are mostly 2x6s with 4x6s spaced about 8' apart supported by large brackets. We had planned to use closed-cell spray foam insulation in order to get the maximum r-value in the relatively shallow rafter bays. Also, we want to maximize the available head room in the second floor rooms. The underside of the roof will also be the ceiling with t&g beadboard installed directly to the rafters.

Asked By Jodi Gunderson | May 29 15
2 Answers

Overinsulating or underinsulating?

We have a home built in 1986 in Columbus, Ohio (Zone 5). We are replacing our siding due to hail damage and plan to have the following layers on our home:

Existing:
1. drywall
2. 2x4 walls with unfaced batt fiberglass insulation (R?)
3. polyiso 1/2"? - (old, some gaps, foil faced, says "R3.6" on the face)

New:
4. 3/8" EPS w double foil face (~R1.5) - http://www.thermalbuildingconcepts.com/technical/propertySheet/ps-Physic...
5. Tyvek
6. Cedarmax insulated vinyl siding (R2.4) - http://www.proviaproducts.com/productdetail/vinyl-siding/cedarmax/

Asked By Chad B | May 27 15
17 Answers

Unvented roof underlayment and rafter bay insulation

Hi guys...first time poster, love the site its been a huge help. I've just finished framing my home in Montana and am ready to move on to the roof. It consists of multiple single pitch decks ranging from 1.5" - 2" in 12. Framing is 2x12 rafters.

Asked By Adeeb Hattar | May 27 15
1 Answer

Is cellulose fiber insulation treated for mold/water infiltration?

how durable is cellulose fiber insulation on a typical say 3 bedroom family house, will it typically last 20 years under normal usage conditions.

Asked By Alice Onaga | May 27 15
10 Answers

Building wrap as an air barrier above a cathedral ceiling?

Hello,
I'm building a small house in Alaska with a 12/12 cathedral ceiling. I'm planning on a 1 1/2" vent channel above the fiberglass batts I will be using. Venting will be the usual eave to ridge vent design.
I've been advised to create an air barrier above the batts so they aren't wind washed by air traveling up the vent channel.
I haven't been able to find much information on this approach, and none of the builders in my area are familiar with it. Can anyone supply me with some "do's and don't's" one this technique?

Asked By Justin Smith | Apr 2 15
3 Answers

Insulating an old home

working on an old house, removed lathe down to the studs and the outside clapboard siding. There was no sheathing so what is exposed is the horizontal clap board siding. What is your recommendation for insulating the outside walls. Is it possible to use foam insulation (closed cell or open cell foam) directly against the siding or do I need some kind of air space between? If an air space, would15# black felt paper against siding be sufficient? the back side of the siding has never been painted. Siding is pine and 140 years old. Would appreciate any input.

Asked By John Conway | Feb 24 15
5 Answers

Is there an energy efficiency penalty for an oversized dehumidifier?

If i buy one that is oversized for my basement it will presumably run fewer hours a day at higher wattage, is there any penalty or lower effectiveness on this?
The one i am considering is 1.85L/kWh energy star rated compared to another 1.85L/kWh unit.

Asked By Alan B | May 22 15
7 Answers

New high-rise condos

I read about a large scale high-rise condos being built in downtown Phoenix. What I was surprised at was there is nothing mentioned about energy efficiency. We are talking Arizona and no solar panels are being used to offset the electricity. There is no LEED certification being sought. Nothing about how energy efficient the building will or will not be.

http://www.portlandparkcondos.com/team/

Asked By Peter L | May 24 15
3 Answers

Passive solar orientation and shade-free zone

Friends,

I am writing to double-check my thinking on our passive solar building orientation and a shade free zone.

Next week a surveyor will stake out the building layout for our 1,100 sq foot passive solar home at 46 degrees N in Minnesota.

The structure's southerly, solar-gain wall will be oriented at 210 degrees (30 degrees W of true south). Solar studies I have done show that we will get good sun light penetration into the structure during the winter with this orientation.

Asked By Randy Bunney | May 13 15
8 Answers

Critique for gut-job re-do — insulation

Hi,

Asked By Brian Greul | May 11 15
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