Demilec Insulation Removal & Replacement Nationwide | Walt’s Insulation

Demilec Insulation Removal & Replacement in Sunnyvale: What to Know First

We remove and replace Demilec spray foam and injection foam insulation throughout Sunnyvale, typically completing most attic jobs in one to two days. As an independent Demilec service provider, we’re not tied to the manufacturer’s warranty process, which means we diagnose problems honestly and recommend replacement only when it actually saves you money. Call (669) 215-4805 and a live person answers, 24/7, no voicemail and no answering service.

Call (669) 215-4805

This page is for Sunnyvale homeowners who have Demilec insulation that’s failing, wet, contaminated, or simply underperforming. Whether it’s Heatlok HFO Pro in an attic, Sealection 500 in walls, or an older pour foam that’s crumbling, you’ll find straight answers here about what went wrong, what it costs to fix, and how we handle the job from start to finish.

How Demilec Products Fail, and How We Fix Them

• Heatlok HFO Pro shrank away from roof decking. We see this often in Sunnyvale homes built between 2015 and 2020, especially along the El Camino corridor where afternoon attic temps climb past 140 degrees. The foam pulls back from rafters, leaving thermal gaps that show up as hot bedrooms upstairs. The fix isn’t patching. We remove the delaminated sections and re-foam, then verify coverage with a thermal camera.
• Sealection 500 soaked through after a roof leak. Open-cell foam absorbs water like a sponge. A small leak near a vent pipe or chimney can saturate large sections without anyone noticing until the drywall stains. Because open-cell foam holds moisture against framing, we remove the wet material completely, dry the cavity, and replace with closed-cell Heatlok HFO Pro in moisture-prone areas. Patching wet open-cell foam just moves the problem deeper into the wall.
• Older Demilec pour-in wall foam settled and left voids. Sunnyvale’s older ranch homes near Murphy Avenue sometimes have Demilec’s pour foam from the early 2000s. Over time it compacts and pulls away from studs. We remove what’s left with a specialized vacuum system, then dense-pack the wall with Knauf Jet Stream or CertainTeed InsulSafe to restore the original R-value without opening interior walls.
• Rodents tunneled through attic foam. Rats and mice love burrowing through open-cell foam. We’ve pulled Demilec attic foam out of homes near Ortega Park where the top layer looked fine but the bottom was Swiss cheese. After removal, we address the entry points, sanitize, then re-insulate. Walt’s does the rodent proofing in-house, so you’re not coordinating two companies.
• Off-ratio foam that never cured properly. Spray foam sprayed too cold or with a clogged nozzle can stay gummy or emit an odor for years. We’ve removed Demilec foam in Sunnyvale homes where the original installer mixed on-site improperly. This one’s a full removal, every time. There’s no way to fix off-ratio foam from the outside.

Our Demilec Insulation Removal & Replacement Process

1. 1
   We assess first, recommend second. Walt Brenner’s rule since 2000: the wrong product installed perfectly still wastes your money. We inspect the existing Demilec insulation, take moisture readings, and check for air sealing issues before quoting anything.
2. 2
   You get a written quote with real numbers. Upfront pricing, no vague “we’ll see how it goes.” We tell you exactly what we’re removing, what we’re installing, and what it costs.
3. 3
   We decide on parts and products together. For re-foam jobs, we recommend Demilec’s current product line where it makes sense, and we’ll tell you honestly if a different manufacturer’s product fits your home better. We install Owens Corning, Rockwool, Icynene, Johns Manville, CertainTeed, Demilec, Knauf, and GreenFiber.
4. 4
   Removal day. Our uniformed, background-checked techs set up containment, run commercial HEPA-filtered vacuums, and bag everything for disposal. We treat your home like our own, which means drop cloths on the floors and a sweep-out when we’re done.
5. 5
   Replacement and air sealing. New insulation goes in, and we seal the attic floor penetrations that undermine any insulation, including Demilec’s. Good insulation should be invisible, you only notice it when it’s missing.
6. 6
   The Done Right Promise. Every Demilec removal and replacement carries our lifetime workmanship guarantee. If it’s not done right, we make it right. No runaround, no “that’s not covered.”

What Demilec Insulation Removal & Replacement Costs in Sunnyvale

Demilec insulation removal and replacement in Sunnyvale typically runs from $2,800 to $9,500 depending on square footage, accessibility, and the condition of what’s coming out. Here’s what we’ve seen on recent jobs:

• Partial attic foam removal (contaminated or rodent-damaged): $2,800 to $4,200 for up to 800 square feet
• Full attic foam removal and re-foam with Demilec Heatlok HFO Pro: $4,500 to $7,800 for a typical 1,200 to 1,600 square foot Sunnyvale ranch
• Wall cavity foam removal and dense-pack replacement: $3,200 to $5,500 per wall section, depending on stud spacing and access
• Whole-home Demilec removal and replacement (attic plus walls): $7,000 to $14,000 for older Sunnyvale homes near Murphy Avenue or the Cherry Chase neighborhood

What moves the price: how much foam has to come out, whether we need a lift or ladder work, and whether rodent remediation or sanitizing is part of the scope. Call (669) 215-4805 for a free estimate. No trip charge in our county, and we’ll give you a free second opinion on any written estimate you already have.

Why Sunnyvale Homeowners Call Walt’s Insulation for Demilec Work

We’ve been the one down the road since 2000. Walt’s Insulation is locally owned and owner-operated, with a published address and license number. You call, a live person answers at (669) 215-4805, and you’re talking to someone who knows insulation, not a scheduler reading a script.

Our techs know Demilec products because they’ve removed and replaced them in Sunnyvale homes for years. When we say a Heatlok job went wrong, we can point to the exact symptom and explain what caused it. And if Demilec isn’t the right replacement for your home, we’ll tell you that too. We also work with Reflectix radiant barrier products when an attic needs reflective insulation, and we stock materials from Owens Corning, Rockwool, Johns Manville, Knauf, and GreenFiber.

Every Demilec removal and replacement is backed by the Done Right Promise, our lifetime workmanship guarantee. Seniors and veterans always get 10% off. And if you have a written estimate from another company, bring it in. We’ll give you a free second opinion, no pressure and no obligation.

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