Demilec Home Energy Audit in San Jose: What to Know First
An independent Demilec home energy audit in San Jose typically runs $199 to $450 depending on square footage and how many tests you want done, and most audits are completed the same week you call. We perform blower door tests, thermal imaging inspections, insulation assessments, and duct leakage testing on homes with Demilec spray foam throughout San Jose, Los Gatos, Campbell, and the surrounding neighborhoods. If you own a home with Demilec insulation and your energy bills have crept up or certain rooms feel off, call Walt’s Insulation at (408) 837-7384 and a live person will answer. We’ve been auditing and repairing Demilec installations in the Bay Area since 2000, and we’re an independent Demilec service provider, not a franchise or an 800 number.

One thing to know up front: Demilec spray foam is good product. When it’s installed right, it does its job for decades. But “installed right” is the catch, and in San Jose’s older housing stock, we see plenty of Demilec work that wasn’t. That’s where an audit pays for itself fast.
- Key takeaway: Walt’s Insulation provides independent Demilec home energy audits in San Jose with blower door testing, thermal imaging, insulation inspection, and duct leakage testing.
- Key takeaway: Same-week scheduling, upfront pricing, and a lifetime Done Right Promise on any repair work we perform.
- Key takeaway: We’re owner-operated and local. Walt Brenner answers the phone. No voicemail, no call center.
- Key takeaway: Free second opinion on any written estimate, and no trip charge inside Santa Clara County.
How Demilec Products Fail - and How We Find It During an Audit
Demilec makes closed-cell and open-cell spray foam under several lines. In San Jose homes, we most often see Heatlok HFO, Heatlok Soy 200, Sealection 500, and occasionally APEX products. They don’t fail the same way. Here’s what we actually find during audits.
- Heatlok HFO shrinkage at the rim joist. Closed-cell foam can pull away from framing if it was sprayed when the substrate was cold or damp. In San Jose’s older crawlspace and raised-foundation homes, we regularly see a quarter-inch gap at the rim joist that lets outside air pour in. During an audit, thermal imaging shows it as a cold stripe along the floor perimeter. The fix is re-foaming the gap, not replacing the whole assembly.
- Sealection 500 over-spray that never fully cured. Open-cell foam needs proper temperature and humidity to cure. If it was installed during a wet winter week, we sometimes find soft or crumbly patches that lost their R-value. A blower door test won’t always flag this directly, but a thermal scan will show uneven surface temperatures. We cut out the bad section and re-spray with Sealection 500 or a compatible equivalent.
- APEX closed-cell delamination from the sheathing. APEX is a higher-density closed-cell product that can delaminate if the installer pushed too thick a pass. Demilec specifies pass thicknesses for a reason. When foam lifts off the sheathing, it creates a hidden air channel. We find these with a combination of thermal imaging and targeted inspection, then inject or re-foam the void.
- Heatlok Soy 200 with odor complaints. The soy-based closed-cell lines occasionally retain a residual odor if the B-side wasn’t mixed at the right ratio. Homeowners sometimes mistake this for off-gassing concerns. During an audit we check the mix pattern by inspecting foam cell structure, and if the ratio was off, the fix is removal and proper re-application. That’s a warranty issue if the original installer is still around, but most San Jose homeowners call us long after the original contractor stopped answering.
- Gaps around electrical penetrations and can lights. This is less about the Demilec product and more about how it was applied. Any spray foam job is only as good as the prep work. We constantly find un-foamed openings behind outlet boxes and around recessed lights in Demilec homes. A blower door test makes these leaks obvious. Sealing them is a small repair with a big energy impact.
Do it right or do it twice, and we’d rather not see you twice.
Our Demilec Home Energy Audit Process
Here’s how a typical Demilec audit goes when you call Walt’s Insulation in San Jose.
- 1
You call (408) 837-7384. A live person answers, day or night. We ask about your home’s square footage, when the Demilec foam was installed, and what symptoms you’re seeing. Then we schedule your audit.
- 2
We arrive and walk the house with you. Our technician is background-checked, uniformed, and knows Demilec products. We’ll ask where you feel drafts, which rooms run hot or cold, and whether you’ve noticed any odd smells or high bills.
- 3
Blower door test. We depressurize the house and measure total air leakage. In a Demilec home that was sprayed correctly, this number should be low. If it’s not, we know something’s off.
- 4
Thermal imaging inspection. We scan walls, ceilings, rim joists, and attic assemblies with an infrared camera. This shows us exactly where foam is missing, thin, or delaminated, even behind drywall.
- 5
Duct leakage test and insulation inspection. If you have a forced-air system, we check ducts for leaks. We also visually inspect the Demilec application thickness and coverage, and check attic access points and can-light housings.
- 6
You get a written report and an honest recommendation. We’ll tell you what’s leaking, what it’s costing you, and what we’d fix first. If repairs are needed, we quote upfront pricing and back the work with our lifetime Done Right Promise. If the audit shows nothing wrong, we’ll tell you that too, and we won’t invent work.
What Demilec Home Energy Audit Costs in San Jose
We quote audits as a flat fee, not an hourly open-ended charge. For most San Jose single-family homes, here’s the breakdown:
- Basic energy audit with blower door + thermal imaging: $199 to $299 for homes under 2,000 square feet.
- Full audit including duct leakage testing and detailed insulation report: $299 to $450 for larger homes or homes with multiple attic zones.
- Targeted thermal imaging inspection for a specific problem area: $149 to $199 when you already know where the problem is and just need confirmation.
- Repairs found during the audit: Quoted separately with upfront pricing. Sealing rim joist gaps or re-foaming small sections typically runs $400 to $900 depending on access. Full attic re-foam is a bigger job and we’ll give you a firm number before any work starts.
What moves the price is access. Crawlspace rim joist work in an older Willow Glen home with limited clearance takes longer than the same repair in a newer Cambrian house with a full basement. Square footage matters. Number of problem areas matters. We’ll give you the exact number before you agree to anything. Call (408) 837-7384 for a free estimate, and remember, we offer a free second opinion on any written estimate you’ve already received.
Why San Jose Homeowners Call Walt’s Insulation for Demilec Work
We’re the one down the road. Walt’s Insulation has been locally owned and owner-operated since 2000, with a published address and license number. When you call about your Demilec insulation, you’re talking to the people who will actually show up at your door, not a dispatcher three states away. We answer the phone live 24/7, and Walt Brenner himself answers a good share of those calls.
We know Demilec products, but we also work with Owens Corning, Rockwool, Icynene, Johns Manville, CertainTeed, Knauf, and GreenFiber, plus Reflectix for radiant barrier work. That matters because if your Demilec foam has a problem that’s not worth repairing, we can recommend the right replacement without being married to one brand. Every repair we make is covered by our lifetime Done Right Promise. If it’s not done right, we make it right. No runaround, no fine print.
FAQs
Yes, and this is one of the most common situations we see in San Jose. We’re an independent Demilec service provider, so we don’t need the original contractor’s records or involvement. We evaluate the current condition of the foam, run our tests, and give you a straight report. If repairs are needed, we quote them and do the work under our Done Right Promise.
Generally no, but it depends on what the original warranty covers and who issued it. If your Demilec installer is still in business and the foam is under warranty, we’ll tell you that before we touch anything. We never do work that would knowingly void a manufacturer or installer warranty. If the warranty is already dead, which is often the case, our lifetime workmanship guarantee is the only protection you’ll need.
Most audits in San Jose are scheduled within the same week. If you’re feeling a draft or seeing energy bills spike, we can often fit you in within 48 hours. Call (408) 837-7384 and a live person will tell you our next available slot. There’s no trip charge inside Santa Clara County.
In most San Jose homes, repairing the problem areas is far cheaper than replacing the whole installation. We typically find three or four specific leak points rather than a complete failure. A full replacement only makes sense when the original foam was badly installed or failed across most of the building envelope. We’ll show you the thermal images and let you make the call with real numbers.
Yes. Seniors and veterans get 10% off, always, on both audit fees and any repair work. It’s a permanent standing offer, not a seasonal special. We also take $40 off any repair over $200. Mention either when you call (408) 837-7384 and we’ll apply it to your quote.
If your Demilec insulation isn’t performing the way it should, don’t guess. Call Walt’s Insulation at (408) 837-7384 and we’ll schedule an audit, show you exactly what’s happening inside your walls and attic, and give you a straight answer on what it’ll take to fix it. Free estimates, upfront pricing, and a lifetime guarantee on every repair. The one down the road.
Written by Walt Brenner, Owner, Walt’s Insulation at Walt’s Insulation, serving San Jose and nearby areas.