How to seal a crawl space in new constuction?
user-974877
| Posted in Green Building Techniques on
My idea is to put down 10-mil poly before pouring the footings and run the poly into the footings.
Will moisture from the concrete walls be a problem? Is there a better way?
GBA Detail Library
A collection of one thousand construction details organized by climate and house part
Search and download construction details
Replies
Larry,
Greenbuildingadvisor and Joe Lstiburek have some great research and building details on this issue.
http://www.buildingscience.com/documents/digests/bsd-103-understanding-basements/files/bsd-103_understanding-basements.pdf
http://www.buildingscience.com/documents/insights/bsi-003-concrete-floor-problems
Wes
Larry,
Instead of extending the poly that will cover the crawl space floor under the footings, you may find it easier to use a different capillary break at the footings. Many builders install a capillary break on top of the footings after the footings have cured. Options include:
1. Dampproofing
2. Low-permeability paint -- for example, UGL DryLock latex masonry paint
3. Elastomeric paint
4. Delta Footing Barrier.
If you put your floor poly down early in the construction process, it will get dirty and damaged. It's better to put the floor poly down at the end of the job.
For more information, see Building an Unvented Crawl Space.