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3 Answers

What stage to do a blower door test?

I would like to do a test when windows and doors are in.My builder thought when the drywall is done .His concern is the attic space would not be sealed until that time .I am using exterior foam so no interior vapor barrier ....any thoughts?

In General questions | Asked By bob holodinsky | Nov 3 14
1 Answer

Housewrap with rigid insulation

I am in the process of building a home with 3/8 zip sheathing, with two layers of rigid poly iso on the exterior of the sheathing. I have read "Musings of an Energy Nerd - How to Install Rigid Foam Sheathing and it discussed the placement of the WRB. I have installed windows as "outies." Two questions 1. Do I need a house wrap product on the exterior of the foam or will the zip sheathing suffice? 2. If I do need a house wrap how are people installing it over rigid foam?

In Green building techniques | Asked By Christopher McKay | Nov 3 14
2 Answers

Drywall or not?

I am building a house with cathedral ceiling, which will be finish with some pine wooden plank. I remember reading in GBA the necessity to have plastered drywall underneath the wooden plank so it can serve as an air barrier.
In my case I will have some roxul insolation then polyisoyanurate panel then fur strip and then the wood plank, my question is do I still need to have plastered drywall under the wood plank or is the polyiso panel will also act as the air barrier therefore drywall is not necessary.

Please advise
Thank you in advance


In GBA Pro help | Asked By Pierre Gingras | Nov 3 14
1 Answer

Permeability of retrofit insulation in zone 4C

How important is maintaining vapor permeability in a cool humid climate in the case of an insulation retrofit that neither replaces the interior or exterior finish, but merely adds insulation? We'll presume hypothetically equivalent sealing and leak prevention, and equivalent r values. If most moisture comes in through leaks, how much difference will it make to an old zone 4C home whether the in-fill is semi-impermeable, semi-permeable, or quite permeable?

In Energy efficiency and durability | Asked By Lazarus Wentz | Nov 2 14
1 Answer

Kraft paper with flash and batt

I live in Virginia and I have a minimum of one inch of foam board plus spray foam in my old 2x4 walls and am about to install the fiberglass insulation. I bought R-13 insulation with Kraft paper. Should I take the kraft paper off when installing the insulation?


In Green building techniques | Asked By Duane Barron | Nov 2 14
11 Answers

A very low addition...

We've been contracted by a repeat client to build a small dining room addition (11' x 12') attached to a contemporary ranch in Maine. Due to very difficult access issues, the addition has to be supported on sonotubes. Bottom of joists (2x10 with fg batts) will only be 2-3 inches over grade.

In Energy efficiency and durability | Asked By ron letourneau | Oct 29 14
6 Answers

Radon mitigation or ERV for old home with dirt wall basement?

Home was built in 1935 and has 5' dirt and rock walls with a small crawl space above that to the bottom of the upstairs floors which are hard wood when your in the in the basement. Radon measured at 7.7 upstairs above that space. I have a thermopride oil furnace down there also. Radon guys telling me it could cause neg. pressure situation with possible back draft or pull exhaust fumes out of the furnace in the basement area. There is an open walking area the size of a regular sized room where the stairs come down and the furnace and water heater are all easily able to work on

In General questions | Asked By Scott Van Der Veer | Oct 30 14
1 Answer

Insulated office inside a larger building

I have a large structure that is well insulated (50x80 with 18ft ceiling) and I am building a 14x30 office inside of it, with 8ft ceiling. The main building will be conditioned at 55-60 during winter and 80-85 during summer. The office will be conditioned to 72 degrees year round.

My question is about vapor barrier on the office. I am insulating the office walls to R19 and filling the 2x10 ceiling joists with blown cellulose or fiberglass batts. Should I use a vapor barrier on the office and if so, to the inside or the outside?


In Green building techniques | Asked By D Badger | Nov 1 14
1 Answer

Is there a frost risk with underslab inslation?

I was talking with a fellow builder the other day and he asked me if I was worried about frost getting under my slab on grade houses because I use 2" xps insulation under my slabs. I also install 2" xps down four feet vertically along foundation walls. His thoughts were that heat loss from the house often keeps underslabs warmer and frost out.

I am in zone 6.

Your thoughts....

Your thoughts

In General questions | Asked By kye ford | Nov 1 14
4 Answers

Minimum R-values for exterior foam for 2x6 walls

I am building an Arctic entry with 2x6 walls, what is the minimum R-values for exterior foam over my OSB sheeting and house wrap to reduce the chance of moisture accumulation in the walls. I live in Wasilla Alaska, which is zone 7 with about 10,500 Annual Heating Days.

After completing the Arctic entry plan on removing siding and retrofitting all outside walls.

Thanks, all help/info will be appreciated

Craig Steinman

In Energy efficiency and durability | Asked By Craig Steinman | Oct 30 14
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