Demilec Attic Insulation: The West Hollywood Owner’s Guide
If your Demilec spray foam attic insulation is failing, pulling away, or has been chewed through, we stock Demilec-compatible product and typically repair or replace problem areas in West Hollywood for $400 to $900, depending on square footage and how much old foam has to come out first. Most jobs are done same week, and if it’s a small gap or void, we can usually get to it within a day or two. The way most homeowners find us is the same story: an upstairs room that won’t hold temperature, a funky smell that won’t leave, or a utility bill that climbed for no good reason. Then you get up in the attic and find the foam has shrunk, cracked, or something’s been nesting in it.
Which Demilec Models This Applies To
We work with the two main Demilec lines you’ll find in West Hollywood attics: Heatlok HFO (the closed-cell product) and Sealection 500 (the open-cell). The compatibility trick is this: you cannot patch open-cell with closed-cell and expect it to perform. Closed-cell is rigid, structural, and blocks moisture. Open-cell is spongy, breathable, and does not. If someone patches a Sealection void with Heatlok, you get a moisture trap where the two meet, and that’s how you end up with mold in a West Hollywood attic in the middle of summer. We match the chemistry to what’s already up there. Demilec stamps the drum labels with the product name and date code, so we know exactly what we’re working with before we cut anything out. The date code matters too. Foam past about 20 years in a Southern California attic, with the heat cycles those attics go through, is often past its useful life even if it looks okay from below.
Signs Your Demilec Attic Insulation Is Failing
- Rooms directly under the attic won’t hold temperature. If the bedroom over the garage is always 10 degrees hotter than the rest of the house while the AC runs nonstop, you likely have voids or shrinkage in the foam. Closed-cell shrinks when it’s mixed wrong at install, and those gaps get wider every year.
- You smell something earthy or stale that follows you down from the attic hatch. Open-cell foam absorbs moisture, and once the roof leaks even slightly, wet foam stops insulating and starts growing things. We’ve pulled Sealection out of West Hollywood bungalows that weighed triple what dry foam weighs.
- Rodent activity in the attic. Rats and squirrels tunnel through both Demilec products like it’s a hobby. They carve runs, shred the foam, and leave nesting material behind. This just happened in a place off Hayworth Avenue, it’s not rare.
- Your energy bill jumped and you can’t figure out why. Foam doesn’t fail overnight in a dramatic way. It degrades in patches until enough of it has let go that the HVAC is fighting a losing battle, and the bill shows it. Twelve inches of dead foam insulates about as well as nothing.
- Visible gaps, cracks, or pulling-away at the roof deck seams. If you can see daylight gaps around the foam edges or it has pulled back from the rafters, the air barrier is gone. Air moves right around the insulation and the whole system stops working.
Replacement Cost & What’s Included
In West Hollywood, expect to pay $400 to $900 for a targeted Demilec attic repair. Here’s what that includes: we remove the failed section of foam, address whatever caused the problem (a leak, a rodent entry point, old air sealing that failed), then re-apply Demilec-compatible foam matched to your existing product. If it’s a full attic re-insulation with Demilec, that’s a different animal and we’ll give you a line-item estimate before anything starts. What drives the range here is access and prep. Tight attics in older West Hollywood homes with low roof pitches take longer and cost more. The warranty side matters too. Every Demilec repair we do falls under the same Done Right Promise we’ve stood behind since 2000. If it’s not done right, we make it right, no runaround. And right now, we take $40 off any repair over $200. Mention it when you call.
DIY or Call Us?
You can inspect safely. That means opening the attic hatch, shining a light, and looking for the signs we listed above. You do not need to crawl around in a hot attic to do that. What you should not do is buy a DIY spray foam kit and try to patch Demilec yourself. The two-part chemistry has to be mixed at the exact right ratio and temperature or the foam cures wrong, sometimes days later, and you’ve made the problem worse. There’s also the fact that foam expands as it cures, and in a tight attic cavity it can push on the wrong things. If your foam has failed, the smart move is to have someone who knows Demilec products look at it, figure out why it failed, and fix it so it stays fixed. Call (213) 527-4062 and we’ll talk through what you’re seeing up there.
FAQs
Properly installed Demilec closed-cell foam lasts 20 to 30 years in a West Hollywood attic, sometimes longer. But the attic heat in this part of LA is brutal, and poor original installation shortens that fast. We’ve seen foam fail at year eight because the installer rushed the mixing. Open-cell Demilec runs closer to 15 to 20 years before it starts losing performance, just because it naturally degrades faster than closed-cell. If yours is pushing those ages and you’re noticing uneven room temperatures, it’s time to get it looked at. Call us at (213) 527-4062 and we’ll schedule a look.
Yes, in most cases. If the failure is localized, which is what we see most often, we cut out the bad section and reapply compatible Demilec foam. Full replacement is only needed when the failure is widespread, or the foam has been soaked by a roof leak, or you’ve had rodents living in it long enough to wreck the product. The fastest way to know which situation you’re in is a quick phone call. We’ll tell you what you’re likely dealing with before we ever show up.
Most targeted repairs take half a day. That includes removal, prep, foam application, and cleanup. Larger sections or full attics can run a full day or two. We keep our schedule flexible for West Hollywood homeowners because the city tends to bake in summer and attics get dangerously hot by mid-day. We’ll time the work so it’s done safely.
Yes. We run Demilec-compatible foam on our trucks so we aren’t driving back across town to grab materials. We’re an independent service provider, not affiliated with Demilec, but we’ve installed and repaired their products for years, along with Owens Corning, Rockwool, Icynene, and Reflectix where it’s the right fit. If you have a Demilec attic issue in West Hollywood, we can usually fix it in one visit. Call (213) 527-4062 for a free estimate, and ask about the $40-off-any-repair-over-$200 offer. Live person answers, always. We do the job right the first time, because coming back to fix it isn’t good for either of us.
Written by Walt Brenner, Owner, Walt’s Insulation at Walt’s Insulation, serving West Hollywood and nearby areas.