Demilec Spray Foam Insulation in Los Angeles: What to Know First
We provide independent Demilec spray foam insulation in Los Angeles, with most attic and wall jobs completed in one day and a written price delivered before any work starts. Typical Demilec open-cell and closed-cell retrofits in this market run $2,800-$6,400 depending on cavity depth, square footage, and whether the existing substrate needs full removal first. As an independent Demilec service provider, we source materials through authorized distributors and install to manufacturer density and yield specifications without claiming manufacturer affiliation. This page is for Los Angeles homeowners who have a Demilec specification in their building plans, are matching existing Demilec foam in an addition, or need to correct a failed Demilec application from a previous installer. Call (628) 226-1097 for a written estimate.
How Demilec Products Fail - and How We Fix Them
- Heatlok HFO Pro closed-cell shrinkage in unconditioned garage ceilings. The HFO blowing agent achieves a 2.0 lb density at yield, but in Los Angeles garage ceiling applications where summer surface temperatures exceed 140°F on the unconditioned side, we’ve measured 8-12% linear shrinkage pulling away from rafter heels after three to four years. We remove the separated foam, verify the garage is vented per LADBS requirements, then reapply in two 1-inch lifts with a 10-minute inter-pass cooling window rather than one thick pass.
- Heatlok XT low-yield pockets in complex roof decks. The XT series demands precise substrate temperature (minimum 60°F) and consistent hose heat; when previous crews skip the infrared scan, we find cold pockets at valley intersections where the pass was too fast. We cut out the deficient area to substrate, recondition the surface, and reinstall to the published 3.5-4.0 R-value per inch with real-time yield monitoring.
- Demilec open-cell overspray into soffit vents blocking attic intake. In Leimert Park corridor ranch homes with continuous soffit ventilation, we’ve pulled 40-pound blocks of open-cell foam from vented soffit chutes where the installer didn’t mask or block airflow paths. We excavate the blocked chutes, reinstall proper vent baffles, and re-foam with masked intake protection - a step that adds labor but prevents the moisture cycling that rots roof decks in Los Angeles marine-influence zones.
- Heatlok HFO High Lift separation from OSB roof sheathing in coastal humidity. The high-lift formulation saves labor on commercial jobs, but in Redondo Beach and San Pedro installations within three miles of the Pacific, we’ve documented delamination where evening marine layer moisture hit the substrate before the final pass skinned over. We require substrate moisture content below 19% on our meter, schedule starts after 10 AM when overnight dew has burned off, and never spec High Lift within five miles of the coast.
- Demilec foam degradation from incompatible previous insulation contact. When old cellulose or urea-formaldehyde foam was left in place and Demilec was sprayed over it, the residual acids or outgassing can break down the isocyanate bond over 18-24 months. We remove all existing insulation to substrate, HEPA-vacuum the cavity, and apply a primer-sealer where substrate testing indicates pH imbalance - then foam to spec with the documented photo record showing clean substrate before the first pass.
Our Demilec Spray Foam Insulation Process

- 1
Call intake with a live person. We gather the Demilec product name if known, the installation year, the failure symptom, and schedule a site visit - usually within 48 hours in Los Angeles.
- 2
Blower-door test and infrared survey. We pressurize the building to find air leakage paths, then use thermal imaging to map foam continuity, substrate temperature, and moisture anomalies before any material is ordered.
- 3
Written price with scope and product specification. Under Haven Standard Clause 1: flat price, written scope, written warranty before anyone lifts a tool. We specify OEM Demilec resins or, with your approval, equivalent-density alternatives from our Icynene or Johns Manville relationships when Demilec lead times exceed your project schedule.
- 4
Substrate preparation and masking. We seal the holes first. Then measure the R-value. In that order. Top plates, can lights, penetrations, and vent paths are sealed or protected before foam application begins.
- 5
Installation to manufacturer yield and density specs. Real-time monitoring of hose temperature, substrate temperature, and pass thickness; no guesswork on lift intervals.
- 6
Post-work blower-door test and documentation. We hand you the before-and-after CFM50 reading, the installed R-value by cavity, the product data sheets, and the Documented Photo Record. The 365-Day Done Right Promise begins when you sign the completion certificate.
Before
AfterWhat Demilec Spray Foam Insulation Costs in Los Angeles
| Job Type | Typical Range | What Moves the Price |
|---|---|---|
| Open-cell spray foam, standard attic (1,200 sq ft ceiling) | $2,800-$4,200 | Existing removal, access difficulty, need for air sealing first |
| Closed-cell spray foam, garage ceiling (400 sq ft) | $3,200-$5,100 | Shrinkage repair vs. new install, ventilation correction |
| Closed-cell roof deck, conditioned attic (1,000 sq ft) | $4,800-$6,400 | Lift count, coastal humidity protocols, sheathing replacement |
| Rim joist only, crawl space or basement perimeter | $1,800-$3,000 | Accessibility, prior pest damage, vapor barrier integration |
Demilec material costs run 15-20% above commodity open-cell alternatives in the Los Angeles market due to HFO blowing-agent pricing and distributor minimums. Full removal and reinstallation of a failed application adds $1.20-$1.80 per board foot for excavation and disposal. We don’t guess at your number - call (628) 226-1097 and we’ll deliver a written price before any work starts.
Why Los Angeles Homeowners Call Topside Attic Insulation Los Angeles for Demilec Work

We’ve sealed and insulated 9,000-plus homes since 2016, and the ones that go wrong almost always went wrong because someone insulated before they sealed. Wes Okafor runs a blower-door test on every applicable job - a pressurization diagnostic that finds air leakage before a single bag of cellulose or batt goes in - and hands every customer a written summary with before and after ACH50 numbers, installed R-value, and product data sheets. Our technicians are background-checked and uniformed; calls are answered by a live person 24/7. If Demilec lead times don’t match your project schedule, we also install Reflectix and other specified brands with equivalent density and yield documentation. The 365-Day Done Right Promise applies to all completed work, and every job closes with a Documented Photo Record, not available on request - included on every visit.
FAQs
No - Demilec’s product warranty covers material defect when installed to published specifications, regardless of who holds the spray gun. The risk is in undocumented installation: without density logs, pass thickness records, and substrate condition photos, you have no proof the failure was material rather than application. We provide all of that documentation as standard. Call (628) 226-1097 for a free estimate.
Open-cell Demilec is tack-free in 3-5 seconds and fully cured for re-entry in 24 hours under normal Los Angeles conditions; closed-cell Heatlok variants need 24-48 hours before mechanical fastening or finish coating. In February marine-layer periods or near-coastal zones, we add 12 hours and verify with in-situ probe testing before releasing the job. Call (628) 226-1097 to schedule around your occupancy needs.
Spot repair is cheaper when the failure is isolated to one cavity or a single lift with confirmed sound substrate - typically 40-60% of full replacement cost. When shrinkage, delamination, or chemical degradation extends across multiple rafter bays, full removal is more economical than chasing progressive failure. We diagnose with infrared and core samples, then write both options in the same scope so you choose with real numbers. Call (628) 226-1097 for the written price.
Yes - we pull a core sample from the existing foam, measure density and compressive strength, and specify the matching Demilec product from our distributor. Where Demilec has superseded the original formulation, we document the equivalent spec and your approval before application. The key is verifying the existing foam is sound; we won’t tie new work to failing substrate. Call (628) 226-1097 for a compatibility assessment.
Most Demilec projects are scheduled within 5-7 business days of written estimate acceptance, assuming material is in distributor stock. Custom density orders or large commercial Heatlok HFO High Lift quantities can extend to 10-14 days. Emergency air-sealing and temporary insulation is available same-day in most Los Angeles zip codes if conditioned space is compromised. Call (628) 226-1097 - a live person answers 24/7.
Ready for a written price before any work starts? Call Topside Attic Insulation Los Angeles at (628) 226-1097. We’ll run the blower-door test, scope the Demilec work, and deliver a flat price with a written warranty - no voicemail, no callback windows, no surprises.
Written by Wes Okafor, Owner & Lead Insulation Technician, Topside Attic Insulation Los Angeles at Topside Attic Insulation Los Angeles, serving Los Angeles and nearby areas.