Demilec Blown-In Insulation in Santa Clarita: What to Know First
We provide independent Demilec blown-in insulation service in Santa Clarita, typically completing attic jobs in one day with same-day blower-door verification. Most homes we see run between $2,800 and $5,400 for a full attic treatment with air sealing included, and we put that price in writing before anyone touches a ladder. This page is for homeowners who already have Demilec insulation in place and need to know whether it can be topped up, replaced, or paired with new blown-in material to hit the R-value their home actually needs. If you’re reading this because your energy bills climbed or a home inspector flagged thin coverage, call us at (747) 294-2764 and we’ll walk through your attic conditions over the phone.
How Demilec Products Fail - and How We Fix Them
- Demilec Heatlok HFO Pro settled below labeled R-value. The open-cell spray foam was installed at 5.5 inches in a Valencia two-story from 2018, but thermal imaging showed it had sagged to 3 inches near the eaves where summer attic temperatures in Santa Clarita regularly exceed 140°F. We don’t spray over compromised foam. We remove the failed sections, re-establish the air barrier with targeted sealing, then blow in cellulose to the full R-38 depth the Title 24 code requires.
- Demilec Sealection 500 created an impermeable sandwich. This closed-cell foam was applied directly to roof sheathing in a Canyon Country home, trapping moisture against the decking during winter Santa Ana reversals when humid marine air pushes inland. The fix: strip the affected foam, install proper vent baffles to maintain the 1-inch code-required air gap, then dense-pack the rafter bays with blown-in fiberglass that lets the assembly dry to the interior.
- Demilec 500 open-cell shrank away from top plates. We see this in Saugus ranch homes built 2015-2019 where the foam pulled back from framing members, leaving a 1/4-inch gap that blower-door tests reveal as a major leakage path. Our crew traces every top plate with smoke pencil and fills the void with low-expansion sealant before blowing any new insulation. The air seal comes first, always.
- Demilec Eco-Pur contact adhesive failed on knee-wall surfaces. The foam detached from the gypsum in a Stevenson Ranch bonus room above a garage, common where temperature cycling is severe. We mechanically fasten a proper retaining fabric, then dense-pack the cavity with blown-in cellulose at 3.5 pounds per cubic foot so it stays put without relying on adhesive bond.
- Demilec Heatlok Soy 200 degraded from rodent activity. Santa Clarita’s hillside interface means roof rats find attic access through unscreened vents, and they tunnel through open-cell foam for nesting. We remove contaminated material per our insulation removal protocol, rodent-proof with galvanized hardware cloth at all penetration points, then blow in fresh borated cellulose that resists future pest interest.
Our Demilec Blown-In Insulation Process

- 1
Call intake with photo review. You text us images of your attic access, any visible Demilec labels, and your recent energy bills. We identify the product line and flag known issues before we arrive.
- 2
On-site blower-door test and thermal scan. We pressurize the house and record the CFM50 baseline. In Santa Clarita’s dry climate, we pay special attention to top-plate leakage and duct chase bypasses that inflate heating loads during December-January cold snaps.
- 3
Written scope with price. Under Haven Standard Clause 1, you get a flat price, written scope, and written warranty before anyone lifts a tool. No work starts without it.
- 4
Air sealing first, then insulation. We seal every penetration with fire-rated caulk and foam, install baffles at eaves for proper ventilation, then blow Demilec-compatible cellulose or fiberglass to exact depth. For dense-pack wall cavities, we drill and fill at calculated pressure to eliminate voids.
- 5
Post-job blower-door verification and photo record. We run the pressurization test again and hand you a printed report with before-and-after numbers. The report goes home with you. The numbers don’t lie, and you shouldn’t have to take anyone’s word for it.
- 6
Cleanup and 365-Day Done Right Promise activation. Your documented photo record is uploaded same day. If the CFM50 doesn’t drop or the R-value tests thin, we make it right.
Before
AfterWhat Demilec Blown-In Insulation Costs in Santa Clarita
| Job Type | Typical Range | What Moves the Price |
|---|---|---|
| Attic top-up over existing Demilec (R-19 to R-38) | $2,800 - $4,200 | Accessibility, existing depth, whether air sealing is needed |
| Partial removal + replacement (settled or damaged foam) | $4,000 - $6,800 | Volume of material to remove, disposal fees, extent of re-sealing |
| Dense-pack wall insulation (Demilec cavity fill) | $3,200 - $5,500 | Wall area, interior vs. exterior access, finish repair responsibility |
| Full attic strip, seal, and re-insulate | $6,500 - $9,400 | Square footage, ductwork in attic, need for baffle installation |
These ranges reflect what we’ve written on actual proposals in Santa Clarita over the past 24 months, including homes from Newhall to Sand Canyon. Your price depends on what we measure, not what we guess. Call (747) 294-2764 for a free estimate with written numbers you can compare.
Why Santa Clarita Homeowners Call Topside Attic Insulation Santa Clarita for Demilec Work

We’ve sealed and insulated over 9,000 homes since 2016, and a growing share in Santa Clarita started with a Demilec product that didn’t perform as expected. Wes Okafor, who trained in building science at Washburne Trade School in Chicago before moving west, runs every job with the same protocol: seal first, test second, insulate third, verify last. Our technicians are background-checked and uniformed, and when you call (747) 294-2764, a live person answers, 24/7. We also work with Reflectix and other brands, so if your situation calls for a hybrid approach rather than straight Demilec replacement, we’ll tell you that upfront and price it accordingly. The 365-Day Done Right Promise applies to everything we touch.
FAQs
No, topping up with compatible blown-in material does not void the original Demilec product warranty, though that warranty only covers the foam itself against manufacturing defect, not installation error or subsequent modification. We document existing conditions with photos before we start so there’s no dispute about what was pre-existing. If your Demilec was installed by a certified applicator and you have the original paperwork, we’ll review it with you during our free estimate.
Yes, blown-in cellulose at R-3.7 per inch and blown-in fiberglass at R-2.5 per inch can achieve any code-required assembly R-value when installed to proper depth. In Santa Clarita, Title 24 requires R-38 in attics for new work and R-30 for retrofits. We calculate the exact depth needed based on your existing Demilec thickness and target number, then verify with depth markers and thermal imaging before we leave.
Repair is cheaper only when the Demilec is fully adhered, at proper thickness, and the failure is isolated to a small area, typically under 10% of total coverage. Most Santa Clarita homes we assess have widespread settling or adhesion failure that makes spot repair uneconomical. We’ll show you the thermal images and give you both prices, repair and replace, so you can decide with real numbers. Call (747) 294-2764 for that comparison.
Most jobs are scheduled within 3-5 business days of your call, and we complete single-attic work in one day. Dense-pack wall jobs or full removals requiring two days are scheduled consecutively so your home isn’t left open overnight. Emergency situations, such as insulation compromised by active roof leaks, get same-day or next-day response.
As an independent Demilec service provider, we are not restricted to Demilec-only materials. We source from Owens Corning, Johns Manville, Knauf, Rockwool, CertainTeed, Icynene, Demilec, and GreenFiber, selecting the product that matches your existing assembly and performance goals. For blown-in work over Demilec, we typically specify borated cellulose or fiberglass that is chemically compatible with the existing foam substrate and meets California fire-smoke spread requirements.
Ready to see what your attic actually needs? Call (747) 294-2764 for a free estimate with written pricing, or text us photos of your attic access and any visible insulation labels for a preliminary assessment. We serve Santa Clarita, Stevenson Ranch, Valencia, Canyon Country, Newhall, Saugus, and surrounding areas.
Written by Wes Okafor, Owner, Topside Attic Insulation Santa Clarita at Topside Attic Insulation Santa Clarita, serving Santa Clarita and nearby areas.