Demilec Attic Insulation: The San Diego Owner’s Guide
We stock and install Demilec-compatible attic insulation throughout San Diego, with most jobs running between $1,800 and $4,200 depending on square footage and existing insulation condition. Our crew carries Demilec Heatlok HFO and Sealection 500 on the truck, so we can typically match your existing insulation and start same-day when you call before noon. Most San Diego homeowners discover a problem the hard way: a bedroom that won’t cool in August, a spike in the SDG&E bill, or visible gaps where the insulation has pulled away from the roof deck. If you have a Demilec product that’s underperforming, the fastest path to an answer is a free attic inspection with a written price before we touch anything.
Which Demilec Models This Applies To
Demilec makes two closed-cell spray foam lines that show up in San Diego attics: Heatlok HFO and Sealection 500. Heatlok HFO is the high-density option (roughly 2.0 lb per cubic foot) that acts as both insulation and air barrier. Sealection 500 is open-cell, lighter, and typically used where budget matters more than R-value per inch. We also see older Demilec products like Heatlok Soy and Sealection Agribalance in homes built between 2005 and 2015, and those are where failures tend to concentrate. The compatibility gotcha: open-cell foam cannot be patched with closed-cell foam, period. If you have Sealection 500, we match it with open-cell. If you’re not sure which product is in your attic, pull back a section and look for the yellow or cream color of closed-cell versus the softer, spongy texture of open-cell. We’ll confirm it during the walkthrough before writing any estimate.
Signs Your Demilec Attic Insulation Is Failing
- Uneven room temperatures between floors. Closed-cell foam loses its air-sealing ability when it delaminates from the roof deck, letting hot attic air push into the living space below.
- Higher summer electric bills with no change in usage. San Diego’s coastal marine layer means attics trap moisture, and moisture intrusion degrades foam’s R-value faster than most manufacturers admit.
- Visible gaps or cracks in the foam surface. We regularly see shrinkage in older Heatlok Soy installations in East County, especially along the roofline where heat builds during July and August.
- Musty odor in the attic or top-floor rooms. This usually means moisture got between the foam and the roof sheathing, a problem that compounds quickly in humid La Jolla or Point Loma attics.
- Pest activity or rodent droppings near the eaves. Gaps in spray foam are an open invitation to rats and mice, which are an unfortunate reality in every San Diego neighborhood from Chula Vista to Carlsbad.
Replacement Cost & What’s Included
In San Diego, removing failed Demilec foam and reinstalling typically runs $6 to $9 per square foot for closed-cell Heatlok HFO, and $3 to $5 per square foot for open-cell Sealection 500. Removal of old foam adds $1 to $2 per square foot depending on how well it’s bonded to the sheathing. Every quote we write includes removal, disposal, new material, labor, and a full attic cleanup. You get a written price before any work starts, and the job is covered by our 365-Day Done Right Promise: if the repair doesn’t hold, we return free and make it right. No add-ons, no surprise line items, no “while we were up there” charges. Garrett Sloane walks every attic personally before quoting because he’d rather tell you what you actually need than sell you square footage you don’t.
DIY or Call Us?
You can safely check your attic for visible gaps, dark staining, or foam that has peeled away from the decking. A flashlight and five minutes will tell you whether there’s an obvious problem. Beyond that, installing spray foam is not a weekend project. Closed-cell foam requires professional equipment, proper ventilation during application, and a respirator, and if mixed wrong the chemical reaction can create unsafe conditions in an enclosed attic. We also see DIY attempts where homeowners sealed over a roof leak with fresh foam, trapping moisture against the sheathing and turning a $400 patch job into a $6,000 roof deck replacement. If you’re in San Diego and your Demilec insulation is suspect, call (858) 282-0169. We’ll inspect it, tell you what’s wrong, and give you a written price before anything gets sprayed.
FAQs
Properly installed and kept dry, Demilec closed-cell foam lasts 30 to 40 years in San Diego’s climate, but open-cell Sealection typically starts losing its seal around 15 to 20 years due to moisture absorption from coastal humidity. We see the most premature failures in west-facing attics that bake all afternoon during summer heat waves. Call (858) 282-0169 and we’ll assess your specific install, free.
Small gaps and cracks can often be spot-patched with matching foam, which costs $400 to $900 for most San Diego attics. If the foam has delaminated from the roof deck over more than 15% of the surface, replacement is usually cheaper than chasing patches that keep failing. We’ll show you photos of what we find before recommending either path.
Most Demilec attic insulation replacements in San Diego take one full day for open-cell and one to two days for closed-cell, including removal of old material. Larger attics over 2,000 square feet may run into a third day. We schedule so you’re not waiting around, and our techs show up in a marked uniform with a photo ID and their name sent to you before the visit.
Yes. We keep Heatlok HFO and Sealection 500 on our trucks in San Diego, alongside materials from Owens Corning, Johns Manville, Knauf, Rockwool, CertainTeed, Icynene, GreenFiber, and Reflectix, so we match your existing insulation rather than making whatever we have work. Aspen Attic Insulation San Diego is an independent service provider, not affiliated with Demilec. Call (858) 282-0169 for a free estimate and we’ll confirm what’s in your attic today.
Written by Garrett Sloane, Owner, Aspen Attic Insulation San Diego at Aspen Attic Insulation San Diego, serving San Diego and nearby areas.