Demilec Wall Insulation in Mountain View: What to Know First
We provide independent Demilec wall insulation service in Mountain View, typically completing most jobs in one day with a written price delivered before any work starts. Most Demilec injection foam and drill-and-fill wall jobs in homes built between 1960 and 1995 run $2,800 to $5,400 depending on wall cavity condition and accessibility. Call (669) 259-0406 for a free estimate with a written scope and warranty.
This page is for Mountain View homeowners who have Demilec open-cell or closed-cell foam products in their walls and are dealing with shrinkage, moisture issues, or underperformance, or who need new wall insulation installed where Demilec was specified. We work on Demilec Heatlok HFO Pro, Demilec Sealection 500, and legacy Demilec 500 series products found throughout Mountain View’s Eichler tracts, Rex Manor bungalows, and the custom builds off Cuesta Drive.
How Demilec Products Fail - and How We Fix Them
- Heatlok HFO Pro shrinkage in vented wall cavities. The HFO blowing agent can lose volume in wall assemblies with ongoing air leakage, particularly where top plates weren’t sealed during original installation. We see this in Mountain View’s 1970s ranch-style homes near Rengstorff Park, where seasonal temperature swings stress the foam. Our fix: remove the compromised foam, seal the top plates and electrical penetrations with acoustic sealant, then reinstall to manufacturer’s specified lift thickness.
- Sealection 500 open-cell moisture absorption in north-facing walls. Open-cell foam is vapor-permeable, and when installed without a proper vapor retarder on the warm side, it can hold moisture in Mountain View’s marine-influenced climate where fog layers persist through June mornings. We encounter this on homes along the El Camino Real corridor where exterior sheathing stays damp. Our fix: assess with moisture meters, remove affected foam if degradation exceeds 15% by volume, install smart vapor retarder, then replace with closed-cell or properly protected open-cell per assembly design.
- Legacy Demilec 500 series off-gassing and odor retention. Early-generation Demilec 500 formulations can emit trace amines when overheated, often from recessed can lights installed after the foam. Mountain View’s tight housing stock means occupants notice it fast. Our fix: identify the heat source, install fire-rated LED housings with proper clearance, then treat or remove affected foam sections. We don’t mask odors; we remove the source.
- Drill-and-fill cavity voids from inconsistent pour density. Demilec’s two-component system demands precise temperature and pressure at the gun; when previous installers rushed the job, we find pockets of unfoamed resin or thin spots behind electrical boxes. Our fix: thermal imaging to map voids, strategic removal through interior drywall or exterior siding, then controlled re-injection with real-time density monitoring.
- Exterior wall thermal bridging at Demilec-to-stud interfaces. Foam shrinks slightly away from framing members during cure, creating convective loops that show up as cold stripes in winter infrared scans. This is especially pronounced in Mountain View’s uninsulated 1950s tract homes where studs are true 2x4s, not modern nominal lumber. Our fix: dense-pack the cavity with blown cellulose or retrofit with continuous exterior insulation where cladding replacement is planned, breaking the bridge entirely.
Our Demilec Wall Insulation Process

- 1
Call and schedule. A live person answers 24/7. We book a site visit, usually within 48 hours for non-emergency Demilec work in Mountain View.
- 2
Diagnostic visit with thermal imaging and blower-door baseline. We pressurize the house to 50 pascals, record the CFM50 reading, and use FLIR to map wall cavity anomalies. You get a Documented Photo Record of what we found.
- 3
Written price and scope. Before any work starts, you receive a flat price, written scope, and written warranty. Haven Standard Clause 1: no surprises. Free Second Opinion available on any competing written estimate.
- 4
Air sealing first, then insulation. Seal the leaks first. The insulation has nowhere to go if the air does. We seal top plates, electrical penetrations, and plumbing stacks before touching foam or cellulose.
- 5
Material installation with density verification. For Demilec jobs, we verify pass thickness and cure parameters; for drill-and-fill retrofits, we confirm complete cavity fill with borescope inspection. Before-and-after blower-door numbers are recorded on every applicable job.
- 6
Cleanup, documentation, and walkthrough. You receive the photo record, blower-door comparison if applicable, and written completion certificate. The 365-Day Done Right Promise is in effect from day one.
What Demilec Wall Insulation Costs in Mountain View
| Job Type | Typical Range | What Moves Price |
|---|---|---|
| Demilec injection foam, single-story 1,200 sq ft home | $2,800 - $4,200 | Cavity access (interior drywall vs. exterior siding removal), extent of existing foam degradation |
| Demilec drill-and-fill, two-story with balloon framing | $4,000 - $5,800 | Floor-to-floor sealing requirements, fire-blocking repairs |
| Interior wall soundproofing with Demilec open-cell | $3,200 - $5,400 | Stud bay depth, electrical rewiring needs, STC rating target |
| Demilec removal and replacement (moisture damage) | $5,500 - $8,200 | Extent of removal, sheathing repair, vapor retarder installation |
These ranges reflect Mountain View’s labor market and typical wall construction. Homes in the Monta Loma neighborhood with original 1950s lath-and-plaster require more careful access than later drywall construction. Call (669) 259-0406 for your exact written price; estimates are free.
Why Mountain View Homeowners Call Topside Attic Insulation Mountain View for Demilec Work

We’ve been in Mountain View’s Rex Manor neighborhood pulling out compacted fiberglass batts and replacing them with properly staged blown-in cellulose since before the tech boom made housing here unaffordable for most tradespeople. Wes Okafor learned the sequencing at Richard J. Daley College and spent twenty years refining it up and down the Peninsula. That means we don’t blow insulation over unsealed attic floors, we don’t install foam without checking the dew point, and we don’t leave without handing you the blower-door printout.
We also work with Reflectix and other brands, so if your Demilec assembly needs a hybrid solution or a full material switch, we’re not locked into one manufacturer’s product line. Every job gets the same documentation: written price first, photo record during, performance numbers after. The 365-Day Done Right Promise applies to all completed work. If it’s not right, we make it right.
FAQs
As an independent Demilec service provider, we are not affiliated with or authorized by Demilec, and any remaining original warranty from a certified installer may be affected by third-party work. We document our installation parameters meticulously so you have a record of what was done and how, and our own 365-Day Done Right Promise covers our labor and materials. Call (669) 259-0406 to review your specific warranty status.
Demilec discontinued the original 500 series formulation in the early 2010s, so exact OEM replacement resin is no longer available; we use compatible modern two-component systems from our approved supplier list that match or exceed the original thermal performance, with documented R-values and vapor permeance ratings. For heritage properties in Mountain View’s Eichler tracts where historical accuracy matters, we discuss material options during the free estimate.
Spot repairs make sense when less than 20% of the wall area is compromised and the remaining foam is well-adhered with acceptable density; full removal and replacement is the better value when moisture damage is widespread, shrinkage exceeds manufacturer tolerances, or the original installation skipped critical air-sealing steps. We give you both prices in writing so you can compare the ten-year cost, not just today’s invoice.
Most single-story Demilec injection foam or drill-and-fill jobs are completed in one working day; two-story homes or projects requiring exterior siding removal typically take two days. We schedule within 48 hours of your call for non-emergency work, and our crew arrives with the materials already loaded. Call (669) 259-0406 to check next available dates.
You receive a written completion certificate with the scope fulfilled, a Documented Photo Record of cavity conditions and installation progress, and on applicable jobs, the before-and-after blower-door readings showing your home’s air leakage reduction in CFM50. This is standard on every Demilec wall job we complete in Mountain View, not available on request.
Written by Wes Okafor, Owner & Lead Insulation Technician, Topside Attic Insulation Mountain View at Topside Attic Insulation Mountain View, serving Mountain View and nearby areas.