Community: Green building techniques

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0 Answers

Rigid foam on the roof

We are remodeling the exterior of our 115 year old farm house this year and felt it would be a great time to tighten the envelope and add rigid foam to the exterior. However, our contractor has some concerns about the extra weight of five inches of foam over the roof. Is this a valid concern? It's an old house. The frame of the roof consists of actual 2x4s placed 24 inches apart. We nailed 2x12s to the 2x4s eight years ago to provide a cavity to put blown in cellulose.

Thanks for the advice, Ryan

Asked By Ryan Knight | Feb 11 16
6 Answers

I have a crawl space with cold joints that are inadequately sealed and ooze water. How can I seal them?

I would like to do it healthfully and effectively so I don't have to be concerned about water intrusion in the future.

Asked By Kevin Krafft | Feb 7 16
2 Answers

Can unvented roof assemblies be insulated with fiberglass if I use rigid foam on the exterior of the sheathing?

I have read the Aug 21st post titled "Can Unvented Roof Assemblies Be Insulated with Fiberglass? http://www.greenbuildingadvisor.com/articles/dept/musings/can-unvented-r... I think the answer is "Yes, but...". And here is the but: You need to add the appropriate thickness of rigid foam to the exterior side of the OSB sheathing. I've read so many different roof profile scenarios...I know I ought to be able to figure this out...but I have a few questions...I'm hoping to get some confirmation of my lessons learned as a rookie here on GBA.

Asked By Inger Peters | Feb 10 16
2 Answers

Can I put up 2 kraft-faced batts in a shed roof?

I have a room with a new roof and rafters, and want to install R-30 worth of insulation by installing 2 R-15 3 1/2 inch batts, is it kosher to put one kraft-faced batt on top of another? My buddy John says that is a risk for moisture buildup between the batts but I argue that the kraft paper is not a moisture barrier, There will be a baffle above the batts to allow an air channel from the front (bottom) of the shed roof (with a soffit vent) to the top (also soffit vented)

Thanks!

Tom in Westford, MA

Asked By Thomas Ennis | Feb 10 16
8 Answers

Tiny house building -- mold and off-gassing prevention

Hi, I am going to be building a tiny house DIY. I have not built walls myself, but have done most everything else in a house I had owned, taking it down to the studs to rebuild. One of the reasons I am building a tiny house is that I have extreme health needs. Because of lung disease and a mast cell disorder, I react to small amounts of mold, environmental pollutants (formaldehyde, cigarette smoke), foods, etc. Since these issues have become graver, I have lived in just one place I would consider relatively safe, my current home.

Asked By Emmy Haus | Feb 8 16
33 Answers

Water heater decisions

In the process of building a new house and trying to decide on the best strategy for hot water heating.

We tried to be efficient with our floor plan design, and were able to clump the bathrooms and laundry room in one corner of the 2nd floor of our house. The guest bath is downstairs, almost directly underneath the baths upstairs. The only outlier is the kitchen and a half bath, which is on the other side of the house.

The house is all electric, and there are a couple of things I'm concerned about...

First

Asked By Clay Whitenack | Feb 1 16
1 Answer

Shingle roof over closed-cell foamed rafters

Martin - I'm the architect for a new house. The roof will be:

Wood shingles over
Horizontal strapping over
Vertical strapping over
Grace Ice and watershield over
Plywood sheathing over
Closed cell foam

Do you recommend this? Will there be trouble within the sheathing 'cause it's trapped between two non-breathing membranes: Grace Ice and Watershield (top) and closed cell foam (below)

Many thanks,

Louis Mackall
(you may remember me from Trident launchings in Groton!!)

Asked By Louis Mackall | Feb 8 16
6 Answers

Raised-heel trusses can be annoying

We installed raised-heel trusses with bottom chord overhangs on our house. The top of the top chord is 20" above our top plate. According to the 2012 International Residential Code for seismic zones or zones designated for winds of 100 mph, raised heel trusses more than 15.25" have to be blocked and braced.

Asked By Jimmy Nguyen | Feb 6 16
2 Answers

Wall assembly

If a 4 or 6'' wall works good, what is wrong with a 12'' version of it?

Asked By Michael Abrams | Feb 8 16
4 Answers

Air drying Ponderosa pine

I live in SW Colorado near a sawmill that has a lot of reject 6x6 and bigger ponderosa pine posts and beams that are too warped or twisted too much to be used. Normally these are cut up for firewood but I want to slice them into 3/4" thick end grain tiles, air dry and dimension them and use them for residential flooring. I'll use a moisture meter of course but would like to have a rough idea of time needed for air drying before I start.

Asked By Jack Tally | Feb 7 16
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