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: 9512

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

Craig Foley posted an event
Thumbnail

NESEA BuildingEnergy '15 at Seaport World Trade Center, Boston

March 4, 2015 from 10:30am to 12:30pm
High-Performance, Green Homes in Residential Real EstateInstructor Craig Foley will present three…See More
yesterday
Casey Gesell posted a video

ThermalDry® Insulated Floor Decking!

Larry Janesky, owner and founder of Dr. Energy Saver is once again On the Job insulating and finishing a basement in the northeast – and introducing a brand new insulation product: ThermalDry Insulated Floor Decking. ThermalDry Floor Decking was…
yesterday
Profile IconBergen Heat, Travis Thom and Amita Singh joined Home Energy Pros
yesterday
Tom White's video was featured

U.S. Department of Education Webinar for HVACR Educators

Rebroadcast from On April 30, 2013 Sharon Miller and Robin Utz of the U.S. Department of Education conducted a one hour webinar for HVACR educators to provide them firsthand information from Washington. Highlights include: * A blueprint to revise…
yesterday
Tom White posted a video

U.S. Department of Education Addresses HVACR Educators 4-30-2013

Rebroadcast from On April 30, 2013 Sharon Miller and Robin Utz of the U.S. Department of Education conducted a one hour webinar for HVACR educators to provid...
yesterday
Nate Adams's discussion was featured
yesterday
Bud Poll replied to Bud Poll's discussion CO poisoning in Yarmouth Maine
"Hi Chad, I sure would like to hear the follow-up on what caused the CO issue down there.  As…"
Friday
Chad Mcaulife replied to Bud Poll's discussion CO poisoning in Yarmouth Maine
"I got a call yesterday from a homeowner who had a direct vent furnace installed a year ago and she…"
Friday

© 2015   Created by Lawrence Berkeley National Laboratory.

Badges  |  Report an Issue  |  Terms of Service