Demilec Attic Insulation: The Los Angeles Owner’s Guide
If you have Demilec spray foam or Demilec blown-in attic insulation that isn’t performing, we carry Demilec-compatible products and install them across Los Angeles, typically within a same-day or next-day window. Most Demilec attic insulation work in LA runs between $1,800 and $4,200 depending on attic square footage, existing insulation condition, and which Demilec line you’re restoring. You usually find out something’s wrong when the upstairs rooms stop holding temperature, or when you see patches in the attic where the foam has pulled away from the roof deck.
The good news: Demilec products are well-documented, and matching the right product to your existing system is straightforward once we know what’s up there. The not-so-good news: Demilec open-cell and closed-cell foams behave differently, and mixing the wrong type into a repair creates more problems than it solves.
Key takeaways:
- We stock Demilec-compatible spray foam and blown-in materials on our trucks.
- Written price before any work starts, every single time.
- 365-Day Done Right Promise covers every Demilec attic insulation repair and install.
- Live person answers when you call, 24/7.
Which Demilec Models This Applies To
Demilec makes two main product families for attics: Heatlok HFO, which is a closed-cell spray foam, and Sealection 500, which is an open-cell formula. If your attic was insulated in the last ten years, there’s a strong chance one of these two is up there. You can identify which one by looking at the foam texture: Heatlok HFO is dense and rigid with a slick surface, while Sealection 500 is softer, spongier, and lighter in density.
There’s also Demilec’s Polarcoat line, used less often in residential attics but common in commercial and some larger custom homes. We can match any of these. The compatibility gotcha to know: Demilec’s closed-cell foam cures with a specific density and R-value per inch (Heatlock HFO runs around R-7.4 per inch), and you cannot patch open-cell foam with closed-cell material without creating condensation points at the seam. That’s the kind of mistake that creates mold in an LA attic within one winter. We match like-for-like.
We are an independent Los Angeles insulation contractor, not affiliated with Demilec. We work with eight leading insulation brands including Owens Corning, Johns Manville, Knauf, Rockwool, CertainTeed, Icynene, Demilec, and GreenFiber, plus Reflectix for radiant barrier applications. That matters because we’re not married to one manufacturer: the recommendation fits your attic, not whatever happens to be on the truck.
Signs Your Demilec Attic Insulation Is Failing
- Upstairs rooms run 8 to 12 degrees hotter than downstairs in summer. When sprayed foam pulls away from the roof deck or settles, the thermal barrier breaks. In Los Angeles attics, where summer roof deck temperatures regularly exceed 140°F, that gap transfers heat fast.
- Visible gaps or cracks between foam and framing. Demilec closed-cell foam can separate from wood over time as the house shifts. Even a quarter-inch gap cuts R-value performance significantly.
- You find foam crumbs or dust on stored items. Open-cell Sealection breaks down faster when exposed to UV or repeated moisture. Crumbling foam means the material is degrading and losing its air-sealing properties.
- Higher energy bills without a rate increase. If your summer or winter bills jumped 20% or more and nothing else changed, the attic insulation is the first place to look.
- Rodent or pest activity in the attic. Rats and squirrels tunnel through spray foam, especially open-cell. The tunnels create thermal bypasses and leave droppings that degrade air quality.
Replacement Cost & What’s Included
For a typical Los Angeles attic, here’s what Demilec-specific work runs:
- Partial foam repair (one section, under 200 sq ft): $800 to $1,500
- Full attic re-foam (800 to 1,200 sq ft, open-cell Sealection): $2,400 to $3,800
- Full attic re-foam (800 to 1,200 sq ft, closed-cell Heatlok HFO): $3,200 to $5,500
- Blown-in Demilec-compatible fiberglass or cellulose over existing insulation: $1,800 to $2,800
What moves the price: attic access (crawlspace attics cost more than walkable ones), extent of old insulation removal, and whether we’re doing spot repair or full replacement. Every quote includes the material, labor, cleanup, and our written guarantee. We hand you the price before any work starts. That’s The Kingswell Way, and we don’t make exceptions.
Call (213) 232-7269 and we’ll give you an exact written number for your attic.
DIY or Call Us?
Here’s where we’re blunt: open-cell and closed-cell spray foam should not be applied by homeowners. The two-part chemical reaction generates heat, the equipment requires training to operate safely, and improper mixing creates off-gassing or foam that never cures properly. We learned this trade at Los Angeles Trade-Technical College and it still took years of fieldwork to get consistent results. DIY spray foam kits sold at big box stores produce foam with roughly half the R-value per inch of Demilec Heatlok HFO, and they fail in LA attics within a few seasons.
What you can safely do: inspect your attic visually, note where foam has separated or crumbled, take photos, and check your energy bills. Then call us. We’ll come out, assess what’s actually failing, and tell you straight whether you need a repair or a full re-do. Estimates are free.
We answer the phone live, 24 hours a day. No voicemail. No automated system. Call (213) 232-7269 and a real person picks up.
How a Demilec Attic Insulation Job Runs With Us
We follow The Kingswell Way on every job, and we name it because you should know what to expect. It works like this: we come out, inspect the attic, and give you a written price before any material gets loaded. We commit to an arrival window and we’re in it. We cover floors and furnishings, and we leave the job site cleaner than we found it. Then we put the guarantee in writing: 365 days. If the insulation isn’t performing right within that year, we come back and fix it at no charge. No fine print, no call-back games.
Our techs are background-checked and uniformed, so you know exactly who’s walking into your home. Glenn Hartley grew up in Sylmar, where summer heat in an uninsulated house was just how it went, and he’s been doing this across the LA basin for going on two decades. Good insulation shouldn’t need a sales pitch – the energy bills tell the story.
FAQs
Closed-cell Demilec Heatlok HFO should perform for 25 to 30 years in a properly sealed LA attic, while open-cell Sealection 500 typically lasts 15 to 20 years before meaningful degradation. The two things that shorten lifespan faster than anything here are UV exposure (if foam is near a skylight or open vent) and rodent activity. If your attic has either, expect to revisit insulation sooner. Call us at (213) 232-7269 for an inspection and we’ll tell you exactly what you’re working with.
Yes, if the failure is localized, like a single section that pulled away from the roof deck or a tunneled area from pests, a spot repair works and we do those regularly. If foam is crumbling across multiple areas or the original install was thin, full replacement costs less in the long run than chasing patches. We’ll show you photos from your attic and let the condition speak for itself before we recommend anything.
Most Los Angeles attics take one full day for removal and re-installation, sometimes two if the attic is large or access is tight. Spot repairs run three to four hours. We give you an arrival window and we’re in it, every time.
We keep Demilec-compatible open-cell and closed-cell materials, plus blown-in fiberglass and cellulose, stocked on our trucks for common attic sizes. Specialized orders, like a large Heatlok HFO application or a custom thickness, get scheduled with the material delivered before your install date. You’ll know which applies to your job before you sign anything.
Get a Written Price for Demilec Attic Insulation in Los Angeles
If your attic insulation is failing, you want a straight answer, a fair price, and a crew that shows up when promised. That’s what we do. Call (213) 232-7269 and we’ll schedule your free attic inspection, give you a written price before any work starts, and back the whole job with our 365-Day Done Right Promise. A real person answers, day or night.
Written by Glenn Hartley, Owner, Woolsey Insulation Los Angeles at Woolsey Insulation Los Angeles, serving Los Angeles and nearby areas.