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2 Answers

XPS outgassing?

Saw some used Dow Grayboard advertised as R5/inch and 25psi, which might work well for my basement floor retrofit (zone 5). The R-value is printed on the product, but I wasn't able to find anything on the compressive strength other than a vague reference to a possible value of 15psi. While researching though, I saw some references to long-term outgassing of XPS, as opposed to EPS which apparently outgasses very quickly.

In General questions | Asked By Dave Owens | Feb 26 16
7 Answers

Article on fiberglass's IR translucency

Dana has mentioned fiberglass's IR-translucency several times. In a recent thread, it was identified as contributing to a particular heat gain issue. And I've experienced it myself after having blown fiberglass added to my attic and experiencing a positive difference in winter but a nonexistent to negative one in summer. If I'd known about this before having this work done, I wouldn't have had it done it, either doing it myself or searching farther and wider for someone willing to use cellulose instead of fiberglass.

In Energy efficiency and durability | Asked By Nate G | Feb 24 16
11 Answers

Has anyone tried running ducts through 3-piece crown molding or coffered ceiling?

Hi all,

I am trying to study my lesson before talking with some HVAC pros about ductwork. I am building a 2 story house with a central hall plan. I think a compact duct system is very do-able, because I have a walk-in closet nearby to place the air handler and the ducts won't have very far to go to serve all the rooms. Hoping that a ducted mini split will get the job down so the air handler noise is not a problem.

What I don't have clear in my head is the best way to route the ductwork.

In Interior design | Asked By Clay Whitenack | Feb 22 16
55 Answers

Attic ventilation problem

I am looking for some advice from someone who really understands attic ventilation. I’ve met with several roofing contractors and have received various suggestions on what to do. Having been through the discussions with the contractors I think I have most of the facts which I will provide below. Any help you can provide is appreciated.

House background and location.
1. House built in 1984 in the Philadelphia area
2. We are the original home owners
3. It is a 2 story colonial which faces south
4. The attic area is approximately 900 sq./Ft.

In General questions | Asked By Jim Bruno | Feb 22 16
3 Answers

Why is the interior of our exterior sheeting wet?

Renovation on master bath, took drywall off, then vapor barrier and insulation, house is a very well built ( we built it) 30 yr old home, two story, and noticed inside of exterior sheeting wet? Also whether related or not, have had dark dirty water migrating down outside of vinyl siding, in area of this bathroom. Just had siding replaced 5 yrs ago from aluminum siding. Had typar placed as well, have had many contractors look, seems many suggestions, but no solid reasons why?

In General questions | Asked By Kevin Cotterchio | Feb 24 16
1 Answer

Adding insulation

My wood frame Wisconsin home was built in 1894. Over the years I have been making improvements.
When I take down a plaster and lath wall, I've been putting in insulation and 4-6 mil plastic to tighten things up prior to drywall. I found that upstairs, where the roof meets the outer walls there exists an opening directly to the outside. I assume it's designed that way to circulate air. Is it OK to be sealing that up like I have been doing? Should I be putting in ventilation panels in those spots up to the attic space?

In GBA Pro help | Asked By Jon Reiser | Feb 25 16
6 Answers

Ventilation space on a SIP roof covered by metal roofing

I have a 12/12 pitch cathedral SIP roof that has rot at the seams of the OSB sheathing. Located near Green Bay, Wisconsin. I will need to take off shingles, find and repair gaps between panels, replace rotten patches of OSB, and install a ventilated roof.

In Energy efficiency and durability | Asked By Allan Poole | Feb 24 16
17 Answers

Green roofs and urban heat island

A policy-oriented question for the physics-minded folks out there (Allison?)

I'll try to be brief here.
The question I have here is: How does a 'green roof' performance towards the urban heat island effect compare to a Cool Roof in a hot/dry climate?

In Green building techniques | Asked By Luke Morton | Feb 23 16
1 Answer

Fire proof non-warping foam?

I am an insulation contractor and one of the jurisdictions we work in has begun to demand that fireproof sealants in penetrations to conditioned space from attics and crawlspaces. We have always used a non-warping 1-part foam around electrical and plumbing penetrations. Does anyone know of a non-warping expanding foam that is considered fireproof? We have intumescent caulk that we use in certain areas but many times the holes drilled by the plumbers and electricians are too big to fill with caulk. Thanks for any leads anyone can provide!

In Green products and materials | Asked By Nathan Shirai | Feb 24 16
1 Answer

How best to seal and insulate cantilevered extensions?


In General questions | Asked By Matt Gauger | Feb 24 16
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