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: 9766

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

Hal Skinner replied to Hal Skinner's discussion 'YGRENE' super fund for energy upgrade financing
"Thanks Susan.  It is appreciated."
8 hours ago
Adin Maynard commented on Corbett Lunsford's video
Thumbnail

Beyond Blower Doors: Zonal Pressure Testing

"Great video. Your approach of simplifying the reading as X/50 = percent leaking to outside (with…"
10 hours ago
Chris Dorsi posted an event
Thumbnail

2015 Habitat X Summer National Conference at Big Sky Resort

July 21, 2015 to July 23, 2015
The 2015 Habitat X Summer National Conference will take place at Big Sky Resort, just down the road…See More
11 hours ago
Royce Gleason posted a status
"The passion to learn and gain more advanced energy efficiency techniques, news, videos and much more from home energy pros across the globe."
12 hours ago
Profile IconCristy Kraus, Will Tastad, Royce Gleason and 1 more joined Home Energy Pros
14 hours ago
Susan Davison replied to Hal Skinner's discussion 'YGRENE' super fund for energy upgrade financing
"Hal,   With the above questions, let me first state 'let the buyer beware'. All of…"
16 hours ago
Susan Davison replied to Hal Skinner's discussion 'YGRENE' super fund for energy upgrade financing
"Within California, there are multiple PACE programs available to consumers and business…"
16 hours ago
Chris Dorsi added a discussion to the group International Home Performance Forum
Thumbnail

A Proposal for Expanded International Collaboration

This group was formed in conjunction with an article to be published in the May/June issue of Home…See More
16 hours ago

© 2015   Created by Lawrence Berkeley National Laboratory.

Badges  |  Report an Issue  |  Terms of Service