Demilec Attic Air Sealing Nationwide

Demilec Attic Air Sealing: The West Hollywood Owner’s Guide

We stock and install Demilec-compatible attic air sealing systems in West Hollywood, with most residential jobs running between $1,800 and $3,400 installed depending on attic square footage and penetration count. Same-day service is available when you call before noon, and we carry Demilec APX, Heatlok XT, and Sealection 500 component stock on our trucks. Most West Hollywood homeowners discover their Demilec air sealing has failed when rooms stay cold despite new insulation, or when a recent energy audit flags thermal bypass at can lights and top plates - the exact gaps Demilec spray foam is designed to seal.

Call (213) 306-2607

Which Demilec Models This Applies To

Demilec’s residential attic air sealing line breaks into three series we encounter in West Hollywood homes. The APX series is a medium-density open-cell foam, common in 2015-2020 builds around the Norma Triangle and West Hollywood West; it’s identifiable by the blue-labeled drums and a cured density of roughly 0.5 pounds per cubic foot. Heatlok XT is the closed-cell hybrid, gray in color, rated at 2.0 pcf - we see this in retrofit jobs where the homeowner wanted both air sealing and a vapor barrier in one pass. Sealection 500 is the legacy open-cell formulation, tan or cream colored, still present in older West Hollywood bungalows off Laurel Avenue and Havenhurst.

To identify what you’re working with, check the original invoice or look for a Demilec lot sticker on the attic access hatch - California Title 24 requires the installer to post foam type, density, and install date. If the sticker’s gone, we can sample-cure a small test area in the attic corner to verify density and compatibility before quoting replacement. We use OEM-spec Demilec components where the original formulation matters for warranty continuity; for partial repairs or top-ups, we match with equivalent-density aftermarket foam from our Icynene and Johns Manville stock if the homeowner prefers. Topside Attic Insulation West Hollywood is an independent service provider, not affiliated with Demilec.

Signs Your Demilec Attic Air Sealing Is Failing

• Dust streaks around can lights and electrical boxes. This means conditioned air is escaping through gaps the Demilec foam was supposed to seal, carrying interior dust into the attic. In West Hollywood’s dry climate, these streaks show up within two to three years of a partial or degraded seal.
• Hot second-floor rooms in summer despite running the AC continuously. Failed air sealing lets attic heat radiate through ceiling penetrations faster than insulation alone can block. We measure this with a blower-door test - pressurizing the house to 50 pascals to locate the infiltration paths the foam missed or lost.
• Ice damming or moisture staining on ceiling drywall. When Demilec open-cell foam shrinks or pulls away from top plates, warm moist air hits cold sheathing and condenses. West Hollywood’s mild winters mean this usually shows as brown ring stains rather than full ice buildup, but the mechanism is identical.
• Energy bills climbing year-over-year with no rate increase. A blower-door reading that was 2,800 CFM50 at install and now reads 4,100 tells the story: the building envelope is leaking again, and the HVAC is compensating.
• Visible shrinkage or crumbling at foam edges. Demilec open-cell formulations can shrink 3-5% over time if applied off-ratio or in too-thick passes. We check this with a simple attic walk - no tools needed to spot the gap between foam and framing.

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Replacement Cost & What’s Included

Most full Demilec attic air sealing replacements in West Hollywood run $1,800-$3,400 for attics between 800 and 1,800 square feet. The low end covers a single-zone attic with standard penetrations - can lights, bath fans, a few wire holes. The high end hits multi-level homes in the Hills with complex top-plate geometry, chimney bypasses, and dropped soffits that need full foam rebuild.

Our price includes removal of failed or degraded foam, surface prep with vacuum and primer where needed, application of new Demilec-compatible foam to all top plates, penetrations, and bypass paths, and a post-job blower-door test with written results. We publish before-and-after numbers on every job - a pressurization measurement that shows, in a single figure, how much conditioned air your home was losing before and after the work. Under Haven Standard Clause 1, you get a written price before any work starts, a written scope, and a written warranty. The 365-Day Done Right Promise applies: if it’s not done right, we make it right. We also stock Reflectix radiant barrier components if your attic needs both air sealing and heat reflection.

DIY or Call Us?

Here’s what you can safely check yourself: verify the Demilec lot sticker on your attic hatch, photograph any visible foam shrinkage or gaps, and note which rooms feel drafty or uneven. Do not attempt to apply or remove spray foam yourself. Two-part polyurethane foams generate exothermic heat - temperatures above 200°F if applied too thick - and off-gas isocyanates that require supplied-air respirators and forced ventilation. The chemical ratio (A-side to B-side) is calibrated at the rig; hand-held cans from the hardware store are not equivalent and will fail within a season in West Hollywood’s heat-cycling attic conditions.

We’ve found rat-chewed wiring hidden behind degraded foam in more than one West Hollywood attic, and disturbed without proper lockout it’s a genuine hazard. Call (213) 306-2607 for a free estimate. We’ll bring the blower-door rig, identify every leak path, and hand you a written price before anyone lifts a tool.

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