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4 Answers

How far should poly run up the edge of a monolithic slab on grade?

How far should polyurethane run up the edge of a monolithic slab on grade? If it doesn't run all the way up (as I've seen in some details), should the edge be painted with damp-proofing?


In General questions | Asked By John Ranson | Aug 21 16
12 Answers

Following up on the musty smell in our crawl space

Editor's note: This is a follow-up to a previous thread on GBA. The previous thread was Why do I have a musty mildew type smell in my conditioned crawl space?

In General questions | Asked By Linda Larochelle | Aug 26 16
12 Answers

ZIP system R-sheathing on a Roof

I'm looking for a poor-man's alternative to thick polyiso on a roof and was wondering why ZIP system R-sheathing is not "allowed" to be on a roof? From Huber's web site:

"Zip System R‐Sheathing is currently limited to wood‐framed wall applications only. DO NOT use roofs or light gauge metal framing. For systems requiring multiple layers of water‐resistive barriers, ZIP System R‐Sheathing is intended to replace only the first."

My roof is extremely unique and you will all probably roll your eyes, but here we go:

1. My Roof is vented with baffles

In General questions | Asked By Christiaan Lutzer | Sep 20 16
6 Answers

Low-e? "Do not scrape glass."

I just installed some high end french doors that came with a sticker warning 'DO NOT SCRAPE GLASS". Does anyone know anything about this? Is it some new kind of low E film, have there been long term problems with scraping low E glass?

In Energy efficiency and durability | Asked By William Goodwin | Sep 24 16
35 Answers

Have many questions about HVAC, insulation, and ventilation

I have many questions about HVAC, insulation and ventilation, but will just start with a few. If we decide on an exhaust-only system for a new build home, does also trying to button up the envelope tight work with that type of ventilation?

We will probably insulate with fiberglass blown in at attic floor because spray foaming the whole attic would be so much more expensive. If we don't insulate at roof, do we need to install a radiant barrier at some location to try to bring the heat down in attic?


In Energy efficiency and durability | Asked By C Clark | Sep 21 16
7 Answers

Air sealing

I am in the process of building a new home in zone 5. We are doing a passive solar house with vaulted ceiling in the living room, kitchen and dining room area and the rest of the house will be flat ceilings. I plan to do blown in cellulose insulation on the flat ceilings and closed cell on the vaulted ceiling. I plan to do 3” of rigid foam insulation on the exterior walls with spary in cellulose (2x6) walls. I am also using Prosoco seam filler for the sheathing and Fast Flash for the flashing.

In Energy efficiency and durability | Asked By Michael Brackett | Sep 23 16
1 Answer

Sheet metal over interior studs: Mold issue?

I'm a homeowner / GC who's building a custom home. We're using 1 1/2" Roxul for exterior insulation, 1" closed cell foam on the interior seathing, and cellulose in the remaining 2 x 6 stud cavities.

In Plans Review | Asked By Ryan Lazuka | Sep 23 16
7 Answers

Best insulation method for LP Smartside panels as sheathing & siding?

Building woodshop in cold climate...zone 6-7. Using LP Smart side panels as sheathing and the siding. 190 series, product is .53" thick.

Concerned about condensation on interior side of this sheathing/siding in cold weather. Will dense pack cellulose be fine, or should this siding/sheathing be first sprayed with 2lb closed cell foam?

In General questions | Asked By eric Mikkelsen | Sep 4 16
2 Answers

Wood wool cement acoustic panels in North America?

I came across an interesting product for acoustic control: wood wool + cement panels.

They have a great look:


but the only suppliers I've been able to find are Scandanavian:


Since it seems to just be wood + cement, I was wondering if there are any US or Canadian suppliers.
I'm outside of Portland, OR, and don't like the idea of shipping a container of wood across the world = )

In Green products and materials | Asked By Kevin Lynagh | Sep 23 16
5 Answers

Is it possible to satisfactorily detail single layer of exterior xps square edge sheathing?

Having been directed to an insulation reclaimer I have the opportunity to purchase enough reclaimed xps to sheath my exterior frame though only with a single layer since the 2.5" panel thickness satisfies my requirement. Timberframe has a 2x5 (full dimension) exterior frame that gets cellulose densepack and sheathed with xps that will get 1x4 strapping prior to siding. This foam is square edge and I'm wondering if, in the absence of multiple layers with staggered seams as well as t+g edges, the detailing to adequately seal the seams of the xps will be possible or even approachable.

In Green building techniques | Asked By daniel f. vellone | Sep 23 16
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