CertainTeed Crawl Space Encapsulation Nationwide

CertainTeed Crawl Space Encapsulation: The Westminster Owner’s Guide

Most CertainTeed crawl space encapsulation systems we replace in Westminster run between $3,200 and $5,800 installed, depending on crawl square footage and whether the existing vapor barrier needs full removal. We stock CertainTeed-compatible 10-mil and 15-mil reinforced polyethylene barriers, seam tape, and mechanical fasteners on our Westminster service truck, and we can usually inspect and quote same-day. Homeowners typically notice the problem first as a musty smell that returns within days of running a dehumidifier, or they spot standing water on top of a barrier that has pulled away from the foundation walls.

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Which CertainTeed Models This Applies To

CertainTeed’s crawl space products fall into two lines: the MemBrain smart vapor retarder series and the CertainTeed DryRight reinforced encapsulation system. MemBrain is the thinner, variable-permeance sheet, usually 6-mil, installed in vented crawl spaces that still need some drying potential. DryRight is the thicker, fully sealed system, 10-mil or 15-mil, used in closed, conditioned crawls. The label is printed in the corner selvage of every roll; if yours has degraded, measure the thickness with a micrometer, 10-mil measures roughly 0.010 inch, 15-mil at 0.015 inch.

We do not sell CertainTeed OEM parts; we are an independent service provider with no affiliation to CertainTeed. For Westminster homeowners, we typically install equivalent or upgraded reinforced polyethylene from the same supplier pool, rated equal or higher on puncture resistance and perm rating. The aftermarket 15-mil we carry tests at 67 lbs puncture resistance per ASTM D1709, versus CertainTeed’s published 54 lbs on the 10-mil DryRight. If your existing system was taped with CertainTeed’s red-label butyl tape, know that butyl hardens in our local clay-heavy soil conditions after about 6-8 years; we switch to a modified acrylic tape for Westminster installs that stays flexible longer in high-alkalinity soil.

Signs Your CertainTeed Crawl Space Encapsulation Is Failing

• Water pooling on top of the barrier. This means the seam tape has failed or the barrier has pulled away from the wall termination strip. In Westminster’s compacted clay soils, hydrostatic pressure pushes water through gaps that opened during our dry summers when the soil shrinks and pulls fasteners loose.
• Musty odor returning within 48 hours of dehumidifier shutdown. The encapsulation is no longer blocking soil gas and moisture vapor. A properly sealed crawl should hold below 60% relative humidity for a week or more without active dehumidification.
• Visible sagging between piers or support posts. The barrier has lost tension, usually because the original fasteners were driven into damp wood that later dried and loosened its grip. We see this often in Westminster’s older tract homes near Bolsa Chica Road, where crawl spaces were built with green lumber.
• White or gray powder on the barrier surface. This is efflorescence, mineral salts left behind as moisture moves through a compromised seam. It tells us water is getting between the barrier and the soil, wicking upward, and evaporating at the breach point.
• Rodent damage along the perimeter. Mice and rats follow the foundation wall; if the barrier termination has gaps, they burrow underneath and nest. We document this with photos during inspection, part of our standard Documented Photo Record on every visit.

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Replacement Cost & What’s Included

What drives the range: crawl height (less than 18 inches requires specialized prep), amount of existing debris or failed material to remove, and whether the foundation walls need mechanical fastening or can take adhesive termination. Every job gets a Written Price Before Any Work Starts, flat, with the scope itemized. The 365-Day Done Right Promise covers all encapsulation work, and we deliver a Documented Photo Record showing prepped subgrade, seam overlaps, and final termination details.

DIY or Call Us?

Homeowners can safely check three things: the thickness of their existing barrier with a tape measure or micrometer, whether water is pooling in specific locations, and the condition of the access door seal. Do not enter the crawl space if you smell gas, see exposed wiring in standing water, or if the space is less than 24 inches high and you have mobility limitations.

Where DIY goes wrong: proper encapsulation requires overlapping seams by 12 inches minimum, taping every overlap with pressure-sensitive tape rolled with a weighted roller, and terminating the barrier to the wall at least 6 inches above outside grade. Without a blower-door test afterward, you cannot verify that the crawl is actually sealed from the house above. We’ve re-done three Westminster DIY encapsulations in the past year where the homeowner used 6-mil painter’s plastic and duct tape; the material shredded within 18 months. Call (562) 526-6978 for a free inspection and written price before any work starts.

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