Demilec Vapor Barrier Installation Nationwide

Demilec Vapor Barrier Installation: The Burbank Owner’s Guide

We install and replace Demilec-compatible vapor barriers throughout Burbank, with most jobs running between $1,800 and $4,200 depending on crawl space size and access. Same-day and next-day appointments are available, and our trucks carry Demilec and Reflectix vapor barrier materials so we can usually complete the job in one visit. Most Burbank homeowners discover their vapor barrier has failed when they notice a musty smell coming through the floor, higher indoor humidity, or visible moisture on crawl space framing after a rain. This page tells you exactly what to check, what it costs to fix, and when to call us at (747) 837-5834.

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Which Demilec Models This Applies To

Demilec’s vapor barrier products used in residential crawl spaces fall under their spray foam and coating lines, most commonly paired with Heatlok HFO and Sealection 500 systems. The vapor barrier itself is typically a 6-mil, 10-mil, or 12-mil polyethylene sheet installed over the crawl space floor and lapped up the foundation walls. If you’re looking at a failing liner, the key identifying detail is the thickness and whether it was installed as part of a full encapsulation system or as a standalone ground cover.

One compatibility gotcha we see in Burbank: older homes with piers and post foundations often have vapor barriers that are too narrow for their joist spacing. If the plastic doesn’t extend at least 6 inches up every foundation wall and 12 inches at the seams, it’s not doing its job regardless of the Demilec brand label. We match the replacement spec to your crawl space dimensions and Burbank’s damp-winter reality, not just to whatever was originally stapled down. For most residential applications, a 10-mil reinforced poly is a better long-term value than a 6-mil, especially with the ground moisture we get near the Verdugo Mountains and along the LA River corridor.

Signs Your Demilec Vapor Barrier Installation Is Failing

• Musty odor inside the home. A torn or pulled-back vapor barrier lets ground moisture evaporate into the crawl space, and that damp air rises into your living space through the subfloor. This is usually the first thing Burbank homeowners notice, especially in older homes around Magnolia Park and the Chandler Bike Path area.
• Condensation on crawl space framing or ductwork. When the barrier is torn, relative humidity in the crawl space climbs past 60%, and moisture condenses on cooler surfaces. Over time this rots floor joists and attracts termites, which are already a real concern in this part of Los Angeles County.
• Visible tears, gaps, or pulled-back edges along the foundation wall. Rodents, plumbing repairs, and even past earthquake shifting can pull the plastic away. If you can see exposed dirt, the barrier is compromised.
• Floor feels colder or shows cupping in winter. Moisture wicking through the subfloor causes wood expansion and makes hard floors feel clammy. This is separate from insulation issues, though we usually find both in under-insulated Burbank crawl spaces.
• Mold or efflorescence on the foundation stem wall. White chalky deposits on concrete mean moisture is moving through the wall, which a properly sealed vapor barrier should be managing. Left alone, this degrades the concrete and invites mold into the joist bays.

Replacement Cost & What’s Included

For a typical 1,000 to 1,500 square foot crawl space in Burbank, a full Demilec-compatible vapor barrier replacement runs between $1,800 and $3,200. Larger homes or those with very low clearance (under 24 inches), multiple piers, or extensive rodent damage push the range to $4,200 or more. The price includes removing the old liner, grading the soil where needed, installing a new 10-mil reinforced barrier with properly lapped and taped seams, sealing the edges to the foundation wall with mechanical fasteners and sealant, and a basic site cleanup.

We don’t do vague quotes. Every estimate lists the liner material by thickness and brand, the square footage, and the labor in one line item. You’ll know exactly what you’re paying for before we start, and we honor our upfront pricing. If the work isn’t done right, our 90-Day Done Right Promise means we come back and make it right. Neil Ashford started Warmline Insulation Co. in 2011 and still personally reviews every Burbank crawl space job photo before we call it complete.

DIY or Call Us?

You can safely inspect the visible edges of your vapor barrier. Look for exposed dirt, torn plastic, or staples that have pulled free. You can also check the humidity in your crawl space with a basic hygrometer, anything above 60% in Burbank’s climate means the barrier is underperforming. What you shouldn’t attempt is a full replacement in a confined dirt crawl space. Working on your back under a house with limited clearance, dealing with rodent droppings, sewage line clearance, and potentially sharp pipes or abandoned debris, carries real health and injury risks. We wear full protective gear, use proper lighting, and most Burbank jobs are finished in a single visit. If you want an honest assessment of whether your barrier needs a patch or a full replacement, call (747) 837-5834 and a live person will answer, day or night. We’ll give you a straight answer, not a sales script.

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