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8 Answers

Conditioned crawl insulation--best way to apply?

We are building a new home in NW Oregon (zone 4C) and I am planning a conditioned crawl. The design is based on a lot of reading here and elsewhere, hopefully it makes sense. We have carefully graded the crawl floor to a lowpoint drain and covered the floor with 2 inches of fine gravel. The vapor barrier (Moistop Ultra 6) will extend over the top of the stem wall and capillary barrier to be sandwiched by the mudsill. All the seams will be 6 inch minimum overlap and taped. I am installing 3 inch polyiso foam (R20) on the interior of the foundation wall, over the vapor barrier.

In Green building techniques | Asked By Dave Morgan | Oct 30 13
6 Answers

Spray foam fishy odor

Hello- We just had Gaco Western Wall spray foam installed last Wednesday. The first day it was installed it did not smell and the second day it still did not smell. Those two days the weather was cool and gray. On the 3rd day it was sunny and the house was heating up that is the day the smell started a fish odor. Our walls are not closed up yet. I have contacted the contractor he said this has never happened to him before. I also called Gaco and they said they would contact the sales rep in our area to come over to our house. The smell only happens in the midday.

In Green products and materials | Asked By Diane Fredricks | Oct 28 13
2 Answers

Pressure treated wood house framing

Are any homes built with pressure treated framing?

Is it allowed?

Any health issues?

There are parts of frames that do rot often enough to think PT framing would be useful. Showers toilet floors exterior wall plates window frame areas. Yes of course build right to start with but anyone who works on repairing these areas knows what and why I'm posting this.

Using a bit more PT wood per home would cost little to nothing.

In General questions | Asked By aj builder, Upstate NY Zone 6a | Nov 1 13
13 Answers

Outsulation - best way to install on roof and walls?


I'm building in Whistler BC, Canada (climate zone 6) and I am planning on adding 2" of rigid insulation to the outside of all roof surfaces, and 1" of rigid to all exterior walls (XPS rigid insulation).

The roof is an unvented cathedral ceiling with 10" of spray foam insulation between the engineered rafters. The walls are 2x6 with spray foam insulation.

In Green building techniques | Asked By Duncan Magee | Oct 31 13
5 Answers

Will spray foam at a rim joist affect the wood?

I live in a 150-year-old balloon-frame, stone/brick exterior house in Philadelphia. I have a quote for getting the attic spaces filled with blown insulation (for the first time!) and for air sealing in the basement. Having worked on wooden ships in my past, I'm leery of having closed cell foam applied directly to the rim joist, fearing that it will increase rot potential.

do you share my concern?

In General questions | Asked By Ed Stemmler | Oct 31 13
1 Answer

Exterior foam and vertical vinyl siding

Hello Everyone.

My contractors are about to begin installation of a somewhat protected exterior wall. We'll be applying exterior rigid foam siding and Mastic vertical vinyl siding. I believe we all advocate the use of furring strips between the rigid foam and the siding, but I was just reading the Mastic installation directions and they are suggesting that for their vinyl siding (vertical or horizontal) there be a layer of sheathing between the furring strips and the siding. This strikes me as a poor way to build a rainscreen.

In Green building techniques | Asked By Jason Crawford | Nov 1 13
3 Answers

Airtight drywall approach — very uneven top plates / studs

Hi, I have a question regarding the airtight drywall approach and very uneven top plates. We are currently gut remodeling a post-WW2 single-story Cape Cod.

One of the many issues I face is that the lumber used for the top plates is very uneven. The top plate is a full 2x4” with a 1x4” on the top. the studs are a full 4” wide but in places the top plates are only about 3.5” wide in some places. Also many of the studs require a great deal of shimming just to make the drywall flat.

In Green building techniques | Asked By Shane Fairman | Oct 23 13
3 Answers

Non-toxic, waterproof spray sealant available for drop ceilings?

My landlord put in a drop ceiling in the unventilated bathroom of a ca. 1940s house. The ceiling above remains intact (though should have been removed because of damage from a water leak that has been fixed; the drop ceiling was a quick fix, though hardly ideal given bathrooms are damp).

The chemical smell from the panels is overwhelming and is affecting my breathing. I have a window fan to exhaust the air, but with winter coming this will not be feasible for long and I will have to use a dehumidifier, though that creates heat and increases the toxic smell.

In Green products and materials | Asked By JO McRugg | Oct 31 13
10 Answers

Cathedral ceiling - R-38 plus 1 or 2" of taped polyiso?


I am finishing the cathedral ceiling insulation and I am trying to decide between 1 and 2" of polyiso sheets. It's deep truss design and standing seam steel roof. There is about 12" of void space above installed unfaced R-38, ridge vent, soffit vents.

Just for a reference, walls have cedar shingle siding, 1x4 strapping, 2 layers of taped polyiso, typar, 1/2" OSB, 3+" of 2lbs spray foam and 3/4" T&G pine as wall finish. Probably close to R-40 (about R-25 at framing)

In General questions | Asked By Nick Zees | Oct 30 13
1 Answer

Exterior sealing for straw bale house

About a decade ago a friend built a straw bale house in New Buffalo, MI. Look up its weather to see what challenges it faces.
Moisture is the biggest challenge. He tried for over a year to find a company in the Midwest that would spray a form of concrete onto the exterior or even one that would supply the material so he could spray it himself. The nearest one he found was somewhere between 900 and 1000 miles away in the Southwest.

In Green building techniques | Asked By Lynn Stevens | Oct 31 13
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