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18 Answers

Drainage plane between sheathing and rigid foam

I am working on an addition project located in Wisconsin. My plan was to use Huber Engineering Zip wall sheathing.

In reviewing Zip walls installation instructions, I noticed that Zip calls for a minimum eighth of an inch drainage plane between the rigid foam and the sheathing. In my wall section I planned to include a drainage plain (rain screen) on the outside of the 3 inches of rigid foam.

Will the recommended Zip wall drainage plane reduce the effectiveness of my foam insulation?

In Energy efficiency and durability | Asked By Jason Stringer | Jan 30 11
2 Answers

Air seal my house during renovation

We are renovating a house we bought on the St. Lucie River in Port St. Lucie Florida. I was advised to air seal the house as long as the walls and ceilings are accessible. My contractor has no clue what I am talking about. Please advise how to find a knowledgeable person in the Port St. Lucie area who can assess and advvise. Many thanks

In General questions | Asked By E.S. sHULZ | Mar 20 15
4 Answers

PEX in Chicago: a gamble worth taking?

I've recently begun the renovation of a frame construction two-flat in Chicago. Its two separate apartments with a basement and an unfinished attic. I have researched PEX and would love to use it to replace all the rusting galvanized metal water supply lines. The main advantage for me is that a PEX manifold and homerun-style system would give both apartments equal water pressure during use ( ie. I don't get a cold shower while my downstairs renter does the dishes) BUT Chicago apparently doesn't allow PEX as a potable water supply line.

In Building Code Questions | Asked By Matthew Lamothe | Mar 20 15
1 Answer

How to attach rigid insulation to crawl space floor

I am located in Zone 3B, Orange County Ca.

I am going to seal my crawl space and insulate the walls with rigid insulation. Here is the code from the CEC Residential Compliance Manual:

"Insulation: The R-value of insulation placed on the foundation stem wall shall be

equal to or greater than the wall insulation above the raised floor. Stem wall

insulation shall run vertically along the stem wall and horizontally across the

crawlspace floor for a distance of 2 feet (24 inches)."

In General questions | Asked By keith messick | Mar 20 15
5 Answers

Attic insulation advice/feedback

We recently moved into a 1952 Cape Cod home and will be remodeling the entire 2nd floor attic/living space so now is the time to get the insulation done right. As a result, I have been doing considerable reading on the topic of insulation and would greatly appreciate some advice on my current plan to “cathedralize” and insulate this space.

The plan:
Vent the soffits.
Create a 1 inch deep soffit to ridge ventilation channel in each rafter bay using .5 inch rigid XPS foam board sealed in place with caulk/spray foam.

In General questions | Asked By Chris Kolloff | Mar 18 15
1 Answer


Has anyone seen any study on the relative energy costs and savings of sun tubes? I have a client interested in one of these and I'm not sure if it's a good idea in general.


In Energy efficiency and durability | Asked By Dan Kolbert | Mar 19 15
1 Answer

How do I integrate rainscreen at soffit?

I'm installing a rainscreen (1x4 battens) over 3" of polyiso foam and 3/8" plywood. I'm in Northern CA, zone 3B. My WRB will be Tyvek wrap over the foam. I understand how to terminate and vent the rainscreen at the bottom of my wall, but am not sure what this rainscreen should do at an arched soffit above my door opening.

Attached are a photo of the framed soffit above the door, before installing the rigid insulation. Also is a photo of this detail sketched out.

In Green building techniques | Asked By Dan Burgoyne | Mar 19 15
12 Answers

I live in a basement apartment — The landlord installed insulation (crawl space) giving off a chemical odor

Hi. My landlord installed insulation today behind the walls of my living area. It is giving off an intense chemical smell... Is it safe for my son and I to be ingesting it while we sleep? He was coughing a lot before bed and it made me dizzy.

In General questions | Asked By Caren Donatelli | Mar 18 15
8 Answers

Double vs triple paned on this window quote

Hi all!
I'm wondering if the performance of an identical window moving from double to triple paned will make up for the price difference in the long term (I suspect it will).
Our quote from one company for all windows (Vinyl, Energy Star Rated) is $21k for our new build.
The upcharge to move from double to triple for all windows and doors (fixed and operating) is $1700+tax. Canadian pricing and Zone 7 build.
Would you do it? It seems reasonable to me. I'll attach the quote with window list here in pdf form (hopefully this is kosher).
Thanks in advance for your insight!

In Energy efficiency and durability | Asked By Nik Fiorito | Mar 17 15
19 Answers

Unvented slanted roof with radiant cooling and NO polyurethane in 4C

We are in Everett WA, north of Seattle, right on the coast, zone 4C. I hope that our location will save us...
We have a low sloping steel, west facing roof. Double, 30 weight felt paper underneath to dampen rain noise. I presume 1/2" plywood sheathing. 2x12" rafters, 11" true depth.
We will install WarmBoard R (13/16" thick OSB with aluminum tracks) underneath the rafters for summer cooling and supplemental heating in winter.

In GBA Pro help | Asked By Jan Verschuren | Mar 11 15
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