Sealing crawlspaces and insulating them with polyurethane foam

Joe Lstburek and John Tooley are both sold on sealing crawlspaces.  I saw a short bit of "Holmes Inspections" on HGTV where they sprayed 2 lb polyurethane foam directly onto the dirt floor underneath a raised kitchen addition and sealed the crawlspace essentially turning it into (semi?) conditioned space. I think they sprayed it onto the dirt, I could be mistaken.

My question is: Does it make sense to spray the foam onto the dirt so as to avoid having to install a moisture/vapor barrier, seal it with tape and them add foam on top of that and seal it with tape.

Does anyone have a good supplier of the thick white material that the East Coast companies use on their sealed crawlspaces?

Can anyone direct me to the best practices for such a project? I'm also wondering if someone has a detail for sealing and waterproofing the 12x4 vents in the stucco.

Mr. Tooley stated that sealing/insulating a crawlspace can yield a 15% energy savings. Does anyone have experience with energy savings percentages in California's Central Valley?

It seems that sealing under houses has many benefits but where are the great examples of it done right?

Thanks,

George Matthews

Views: 4621

Reply to This

Replies to This Discussion

Ground cover in the crawl space with have NO effect on foundation movement caused by soil MC. That is an exterior drainage issue.

George,

 

The sealed crawlspace concept is very popular here in North carolina and surrounding states.  The best place to go for answers to your questions is advancedenergy.org and look up in their foundation sealing section.  Some thoughts regarding your questions:

  - It does not make sense to spray foam onto the dirt.  The ground is a surprisingly good insulator.  You want to insulate the peripheral walls of the crawlspace using a code-compliant R-value foam that is approved for exposed use under the Foam Plastics section of the Califormia Residential Code.  In North Carolina, Dow Thermax Sheathing rigid insulation is by far the most popular option and was the one used by Advanced Energy when they built test residences to gauge the effectiveness of sealed crawlspaces.

  - Raven Industries is the most popular manufacturer of poly to cover the ground and flash to the piers and wall insulation.

  - Advanced Energy constructed twelve test houses and determined that a home with a sealed crawlspace should produce about 18% energy savings over a home with conventional foundation vents.  Of course, that data was generated in Eastern North Carolina and results will probably differ in the Sacramento Valley.  The good news for you is that the Advanced Energy Data suggested the bulk of the energy efficiency improvement came during the warm months so some reasonable level of savings should be expected in California.  Humidity levels may impact the amount of that savings.

 

If you have any questions, please feel free to contact medirectly to discuss further

 

Scott Cummings

Sr. Technical Service Engineer

Dow Building Solutions

Charlotte, NC

slcummings@dow.com

I have a question about how to create a termite viewing area in a PU spray foamed foundation wall.

In crawlspace encapsulation one wants to bring the thick white plastic sheet up the foundation wall and make a nice connection with the foam (my insulation contractor does anyway). In doing that how would one create an area of 4" open clear concrete to look out for termite tunnels? Has any solved this problem?

My client who is teetering on the fence about encapsulating his unpleasant smelling crawlspace is thinking of just getting terminix out to inject termite poison into the ground around the perimeter before the project.

Anybody have a great detail for both energy efficiency and termite protection/observation? Thanks!

 

 

There's a good piece on encapsulated crawl spaces here, and it almost-but-not-quite answers your question.

 

http://www.greenbuildingadvisor.com/blogs/dept/musings/building-unv...

RSS

Home Energy Pros

Home Energy Pros was founded by the developers of Home Energy Saver Pro (sponsored by the U.S. Department of Energy,) and brought to you in partnership with Home Energy magazine.

Latest Activity

Jim Gunshinan commented on Jim Gunshinan's blog post My Energy Upgrade California—The Numbers Are In
"Thanks Nate for more good stuff to chew on—and nutritional! We may be running out to Home…"
1 hour ago
Tom Conlon commented on Jim Gunshinan's blog post My Energy Upgrade California—The Numbers Are In
"Jim,I just got around to re-reading your four-part series and I think this is a really interesting…"
1 hour ago
Nate Adams commented on Jim Gunshinan's blog post My Energy Upgrade California—The Numbers Are In
"$50 in health ain't much... not with my crappy high deductible plan. It buys half of a cold…"
1 hour ago
tedkidd commented on Jim Gunshinan's blog post My Energy Upgrade California—The Numbers Are In
"Yep, this thread has some good discussion. Back to dehumidification.  This may be…"
5 hours ago
Jim Gunshinan commented on Jim Gunshinan's blog post My Energy Upgrade California—The Numbers Are In
"Thanks for the clarification Nate. If I had the ability to precisely measure what $50 of health…"
6 hours ago
Nate Adams commented on Jim Gunshinan's blog post My Energy Upgrade California—The Numbers Are In
"Jim, Just a clarification, it's not DEhumidification I'm worried about in your climate,…"
6 hours ago
Chris McTaggart posted events
7 hours ago
Jim Gunshinan commented on Jim Gunshinan's blog post My Energy Upgrade California—The Numbers Are In
"Hi Nate, I'm glad this post has generated so much good discussion, since that is its main…"
7 hours ago
Diane Chojnowski's group was featured
Thumbnail

Facebook Pages

Does your company or organization have a Facebook Page?This group is for pros who have facebook…See More
7 hours ago
Tom White joined Diane Chojnowski's group
Thumbnail

Facebook Pages

Does your company or organization have a Facebook Page?This group is for pros who have facebook…See More
7 hours ago
David Valley's photo was featured

ceiling_infrared

Cold air infiltrating the lower right portion of this wall and ceiling.
7 hours ago
Christopher Morin's 2 blog posts were featured
7 hours ago

© 2014   Created by Lawrence Berkeley National Laboratory.

Badges  |  Report an Issue  |  Terms of Service