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: 11642

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

Videos

  • Add Videos
  • View All

Twitter

Latest Activity

Empower Efficiency added a discussion to the group Job Board
Thumbnail

Position Opening: Local Community Outreach Specialist, Energy Efficiency (San Carlos, CA)

Local Community Outreach Specialist, Energy Efficiency (San Carlos, CA) Job Title: Local Community…See More
yesterday
Amber Vignieri posted a blog post

Elevate Energy Mythbusters: Windows & Attics Edition

This blog post is guest written by former staff member Eric Keeley.Great enthusiasm for home energy…See More
yesterday
Glen Gallo replied to Diane Chojnowski's discussion Poll: What is you favorite or most important home performance diagnostic or measurement tool?
"I agree with Ted. If I could bring just one piece of equipment it would be the blower door. It has…"
yesterday
Glen Gallo replied to Shaun 's discussion Commercial duct testing
"If above the ceiling tiles the wall is a finished assembly and there is insulation on or under the…"
yesterday
Tom White's video was featured

Combustion Appliance Zone Testing (CAZ) Made Easy (March 24, 2016)

Combustion Appliance Zone Testing (CAZ) Made Easy (March 24, 2016) -Gauge Fundamentals -Adapting to the new BPI standard -RESNET testing requirements -NFPA testing requirements -Best practices for best results
yesterday
Profile IconLaura Capps and Bret Abrams joined Home Energy Pros
Thursday
Olivia Taylor posted a blog post

5 Key Reasons Why Rooftop Solar Is Popular In The US

The rapid switch from traditional electricity to clean, economical and renewable solar energy is…See More
Thursday
Adam Swain posted a blog post

Top 5 Tips For Hiring A Crawl Space Contractor

A homes crawl space is one of the few places most homeowners try to avoid at all cost, and for good…See More
Wednesday

© 2016   Created by Lawrence Berkeley National Laboratory.   Powered by

Badges  |  Report an Issue  |  Terms of Service