Hi There Folks,


I came across this crawlspace vapor barrier installed by a BPI contractor. 

Location:  Bay Area of California- near the ocean.  

Environmental Factors:  The area receives a lot of rain, and is notorious for rising groundwater.  

Health Factors:  The customers have respiratory issues, and these were communicated to the contractor.

Material:  6mm visqueen, red tape, nails

Concerns:  The material stops several inches short of the foundation walls. Some seams are taped with red tape.  Held to ground with 8 inch nails. 

I have a lot of respect for this particular contractor, but I have grave questions about how he approaches barrier installation in crawl spaces.

He has responded that this approach is adequate for unconditioned crawlspaces.  


I would appreciate insights, and direction to standards. 

Tags: barrier, crawl, space, vapor

Views: 9479

Attachments:

Replies to This Discussion

I am not sure what the codes say in Cali but (unless I am overlooking it) there is no requirement in the 2009 IRC or IECC for "vented" crawls

For sealed crawls it is;

R408.3.1 Exposed earth is covered with a continuous Class I vapor retarder. Joints of the vapor retarder shall overlap by 6 inches (152 mm) and shall be sealed or taped. The edges of the vapor retarder shall extend at least 6 inches (152 mm) up the stem wall and shall be attached and sealed to the stem wall;

As for the groundwater issue:

R408.6 Finished grade. The finished grade of under-floor surface may be located at the bottom of the footings; however, where there is evidence that the groundwater table can rise to within 6 inches (152 mm) of the finished floor at the building perimeter or where there is evidence that the surface water does not readily drain from the building site, the grade in the under-floor space shall be as high as the outside finished grade, unless an approved drainage system is provided.

As for best practices, especially when a respiratory issue is involved - it is basically what everyone else mentioned - run up the foundation wall a minimum of 6", joints lapped lapped, and every hole, seam, etc... should be taped & sealed per manufacturers directions

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

John Nicholas replied to Sean Lintow Sr's discussion Blower Doors & Methods Used in the group Best Practices (Residential)
"Different houses, different problems, different approaches. A multipoint gives you a slope. The…"
8 hours ago
John Nicholas replied to Sean Lintow Sr's discussion Blower Doors & Methods Used in the group Best Practices (Residential)
"Bud,  I pretty much agree with Sean's points.  Given the time it takes to set up the…"
8 hours ago
Bud Poll replied to Sean Lintow Sr's discussion Blower Doors & Methods Used in the group Best Practices (Residential)
"A multi-point will take longer, but what will it do for the home owner?  Will it change the…"
10 hours ago
Sean Lintow Sr replied to Sean Lintow Sr's discussion Blower Doors & Methods Used in the group Best Practices (Residential)
"Hmmm good question - personally for air-leakage I would go with multi-point, preferably run from…"
12 hours ago
Richard Beyer posted a discussion

Media Reports Spray Polyurethane Foam Insulation spontaneously combusted a $5M Connecticut Home... "The Conclusion"

OFFICE OF THE FIRE MARSHAL1212 WHITTEMORE RDMIDDLEBURY, CONNECTICUT Fire Investigation Report –…See More
23 hours ago
Profile IconDavid Hepinstall and Matthew joined Home Energy Pros
yesterday
Steve Leombruno posted a blog post

Static power energy box

Just wondering if You've heard of this Static power energy box that boasts energy consumption…See More
yesterday
Bud Poll replied to Sean Lintow Sr's discussion Blower Doors & Methods Used in the group Best Practices (Residential)
"Hi Sean, I have a question for you.  If you were only interested in providing the best audit…"
yesterday

© 2015   Created by Lawrence Berkeley National Laboratory.

Badges  |  Report an Issue  |  Terms of Service