Demilec Attic Cleaning & Rodent Proofing in San Jose: What to Know First
We clean and rodent-proof attics with Demilec spray foam and Demilec insulation systems throughout San Jose, usually completing full cleanouts and exclusion work in one to two days. Most Demilec attic cleaning jobs in San Jose run between $1,200 and $4,500 depending on attic size, how much contamination you’re dealing with, and whether the foam needs spot repair after rodents chewed through it. This page is for San Jose homeowners who need straight answers about what’s living up there and what it’ll take to fix it. Call (408) 837-7384 and a live person picks up, day or night.
Key takeaways:
- We’re an independent Demilec service provider in San Jose, not a manufacturer warranty crew.
- Rodents chew Demilec open-cell foam, and their droppings and urine contaminate it. Both need real attention, not just a vacuum pass.
- We back every job with the Done Right Promise, our lifetime workmanship guarantee.
- Free estimates, upfront pricing, no trip charge inside Santa Clara County.
How Demilec Products Fail - and How We Fix Them
Demilec makes good foam. But attics are rough places, and rodents don’t read spec sheets. Here’s what we actually see in San Jose homes.
- Heatlok HFO open-cell foam gets chewed and shredded. Rats and squirrels tunnel through open-cell Demilec Heatlok HFO like it’s a shortcut between rafters. They burrow into the foam, nest inside it, and leave trails of urine that soak deep into the material. The fix starts with removal of the contaminated sections, not just surface cleaning. You can’t sanitize urine-soaked open-cell foam from the outside. We cut out the damaged foam, treat the area, and re-foam or replace as needed.
- Sealection 500 loses its seal when rodents gnaw at the edges. The air-sealing properties that make Demilec Sealection 500 work only hold if the foam stays intact where it meets the roofline and top plates. Rodent chewed edges let conditioned air escape and let hot attic air radiate back into the house. We see this on most San Jose homes where the foam was installed a decade ago and critters found gaps. We repair the perimeter, re-seal the junction, and close rodent entry points before re-foaming.
- Demilec spray foam over rodent droppings is a health mess. When rodents nest on top of existing foam or in the insulation around it, their droppings accumulate and dry out. That dust gets into your HVAC return, into your living space. Attic cleaning here means full decontamination: vacuuming the loose waste, treating affected surfaces, and removing foam that can’t be cleaned. After that, we can apply sanitizer and deodorizer that’s safe for both your home and the foam that remains.
- Demilec foam hides structural damage until it’s extensive. Because Demilec foam bonds tightly to roof decking and framing, rodent damage to wood underneath the foam often goes unnoticed for years. Chewed trusses, gnawed electrical sheathing, wet insulation from urine-soaked nests. Part of our attic cleaning process is inspecting under the foam where possible and checking for hidden damage before we restore and re-seal.
- Borate-treated Demilec products still don’t stop rodents. Some San Jose homeowners are told treated foam keeps pests away. That’s not a rodent deterrent. Mice and rats don’t care about borate. They care about warmth and access. So while the foam itself holds up, the entry points around eaves, gable vents, and roof returns are where the problem comes from. We seal those, then clean up what’s already inside.
Our Demilec Attic Cleaning & Rodent Proofing Process
Every Demilec job starts the same way: we look, we tell you what we found, and we give you a price before we touch anything.
- 1
Inspection and entry point mapping. We go into the attic, document the damage, and find every gap rats or mice are using. On Demilec foam attics, we check the foam-to-roof junctions, vent openings, and plumbing or conduit penetrations.
- 2
Removal of contaminated insulation and waste. Whether it’s loose-fill over foam or damaged Demilec foam itself, we remove what can’t be saved. We use commercial HEPA-filtered vacuums to keep the dust out of the house.
- 3
Sanitizing and decontamination. We treat affected wood, joists, and remaining foam with an antimicrobial cleaner, then apply odor neutralizer where needed. This step is the only thing between you and smelling attic in the hallway every summer.
- 4
Rodent exclusion work. We seal entry points with steel mesh, flashing, or foam-compatible exclusion materials. This is not where you want cheap fixes. A rat can get through a gap the size of a quarter.
- 5
Foam repair or replacement. Where the Demilec foam was cut out or damaged, we re-foam and re-seal. If you have existing Demilec that’s structurally sound, we match the system rather than tearing it all out and starting over.
- 6
Final check and the Done Right Promise. We walk you through what we did, show you photos, and hand you our lifetime workmanship guarantee. Do it right or do it twice, and we’d rather not see you twice.
What Demilec Attic Cleaning & Rodent Proofing Costs in San Jose
Here’s what we quote most often for Demilec attic work in San Jose:
- Basic attic cleanout, no major rodent damage: $1,200 to $2,200 for a typical 1,200 to 1,800 sq ft San Jose ranch or two-story.
- Full attic cleaning with sanitizing and deodorizing: $2,400 to $3,800, depending on contamination level and attic accessibility.
- Full cleanout plus full rodent exclusion and sealing: $3,500 to $5,500 for a whole-home job, including soffit and eave sealing, roof-return work, and vent mesh installation.
- Targeted Demilec foam repair after rodent damage: $800 to $2,500 depending on how much foam needs to be cut out and re-applied.
What moves the price is mostly how much contamination there is, how tight the attic is to work in, and whether the foam needs surgical repair or broader replacement. You’ll get a written, upfront quote before work starts. Call (408) 837-7384 for a free estimate. We answer the phone live, 24/7.
Why San Jose Homeowners Call Walt’s Insulation for Demilec Work
There are plenty of companies in San Jose that’ll clean an attic. There aren’t many who’ll do it with a real name attached to the work. Walt’s Insulation is locally owned and owner-operated. Walt Brenner started this business in 2000 and still answers the phone. No 800 number, no call center. Our techs are background-checked and uniformed, and every one of them knows a Demilec foam attic when they walk up the ladder.
We work with all the major brands, including Owens Corning, Rockwool, CertainTeed, and Reflectix. That matters on a Demilec job because sometimes the right answer isn’t “more of the same.” If a section of foam needs to come out and a different assembly makes more sense for your roof profile and San Jose’s hot, dry summers, we’ll tell you straight. We won’t upsell you a full re-foam just because it’s a bigger check.
The one down the road is the one who answers the phone. We’ve been that company for over 25 years.
FAQs
It shouldn’t, as long as the cleaning and repair work doesn’t damage the foam installation itself. As an independent Demilec service provider, we perform cleaning and rodent proofing in a way that preserves the foam’s integrity. But the reality is most Demilec attics we clean in San Jose are past or near the end of their practical warranty period anyway, and rodent damage already voided portions of it. Call (408) 837-7384 and we can tell you what’s still covered and what isn’t before we start.
Most jobs are done in one to two working days. Smaller attics with light contamination are often a single day from start to finish. If you need us to start sooner, tell us when you call and we’ll work with your schedule. We answer live 24/7 at (408) 837-7384.
Repair is almost always cheaper, and in most San Jose homes it’s the right call. We can match Demilec open-cell and closed-cell products and re-foam just the damaged sections. Full replacement only makes sense when the contamination is so extensive that the foam can’t be cleaned, or when the original install was done badly. We’ll show you the numbers either way, and we give free second opinions if another company quoted you a full replacement you’re not sure about. And remember, $40 off any repair over $200, and a permanent 10% discount for seniors and veterans, always.
Often yes. Call (408) 837-7384 and we’ll get someone out from our service team as soon as we can, same day whenever schedule allows. No trip charge inside Santa Clara County.
It’s almost always rodent urine, dead rodents, or moisture trapped under or inside the foam. Demilec open-cell foam is especially good at absorbing and holding odors because it’s porous. Just running a fan won’t do it. You need the contaminated material removed and the area properly sanitized at the source. We do this all over San Jose, from Almaden Valley to Berryessa to Willow Glen.
Yes. Every job we do carries our Done Right Promise, which is a lifetime workmanship guarantee. If it’s not done right, we make it right. No runaround.
Written by Walt Brenner, Owner, Walt’s Insulation at Walt’s Insulation, serving San Jose and nearby areas.