Demilec Attic Insulation Nationwide

Demilec Attic Insulation: The Austin Owner’s Guide

We stock and install Demilec-compatible attic insulation daily across Austin, with typical full-attic jobs running $1,400 – $3,800 depending on square footage and the Demilec formula you’re matching. Most callers get same-week service, and emergency spray foam jobs can often be same-day when we have crew availability. The usual story we hear starts with a homeowner noticing the upstairs AC running nonstop in July, an attic that feels like a sauna, or energy bills that climbed 30% year over year. You pull back the hatch, climb up, and realize the insulation you paid for is thin, settled, or in some cases was never sprayed thick enough to hit the R-value your home needs in Central Texas heat.

Call (361) 321-0817

Key Takeaways

• Demilec spray foam is a closed-cell or open-cell polyurethane system; matching the right formula to your existing attic matters more than brand loyalty.
• Most Austin Demilec failures we see are installation-related, not product-related: thin passes, off-ratio mixing, or skipped prep work.
• Installed replacement typically ranges $1,400 – $3,800 in Austin; we give a written price before any work starts.
• Spray foam done wrong can trap moisture against your roof deck. This is not a DIY afternoon project.

Which Demilec Models This Applies To

We work with the full Demilec residential line you’re likely to find in an Austin attic: Heatlok HFO Pro and Heatlok XT (closed-cell), Sealection 500 and Sealection Agribalance (open-cell), and Polar Foam products on the closed-cell side. The compatibility question usually comes down to one gotcha: closed-cell and open-cell foam are not interchangeable in the same cavity without a serious plan for moisture movement. If your attic was originally done in Heatlok closed-cell at 2 inches and you’re told you can patch with an open-cell product, walk away from that advice. You can’t.

Identifying what you have is straightforward. Cut a small cube with a knife. Closed-cell feels hard, like a dense foam board, and is typically gray or purple. Open-cell feels soft, spongy, and squishes like a kitchen sponge; it’s usually white or cream. The label on the barrel or the invoice from the original install is even better, but in older Austin homes that paperwork is long gone. For aftermarket equivalents, we carry both Demilec OEM product and equivalent-quality options from other brands we trust. For most patch and remediation work, the aftermarket route saves you 15 – 25% with no practical difference in performance. For warranty-sensitive new construction work, we go OEM.

Signs Your Demilec Attic Insulation Is Failing

• Upstairs rooms run 8 – 12 degrees warmer than downstairs in summer. In an Austin July, that gap means the attic insulation isn’t slowing heat transfer. With Demilec specifically, we often find the foam was sprayed too thin, sometimes under an inch when the spec called for 2 – 3 inches.
• Visible shrinkage or gaps where foam has pulled away from rafters. Off-ratio mixing during the original install causes the foam to cure wrong and shrink over time. You’ll see daylight or gaps at the seams between passes.
• Musty smell or visible mold staining on the foam surface. Open-cell foam in an Austin attic without proper ventilation can hold humidity and grow mold. This is a moisture management problem, not just an insulation problem.
• Your energy bill spiked 25% or more without a corresponding change in usage. Demilec foam should perform for decades. When it doesn’t, the typical cause is installation error, not product failure. The product itself rarely fails quietly.
• Critters have tunneled through the foam. Squirrels and rats in Austin attics will chew through open-cell foam like it’s a suggestion. Closed-cell resists better, but neither is animal-proof.

Replacement Cost & What’s Included

In Austin, a full Demilec attic insulation replacement runs $1,400 – $3,800 for a typical 1,200 – 2,200 square foot attic. Smaller patch jobs and localized fixes start around $700. What drives the number is straightforward: square footage, R-value target, closed-cell versus open-cell formula, and whether we’re removing old material first. Closed-cell runs higher per board foot but delivers roughly double the R-value per inch of open-cell.

Every job we do in Austin includes a written price before work starts, live technician tracking so you know exactly when we arrive, and before-and-after photos delivered to your phone. The 365-Day Done Right Promise covers the workmanship for a full year: if it’s not right, we come back and make it right. That’s in writing, on every job. No hidden line items, no change orders at the door.

DIY or Call Us?

Honest answer: you can inspect a Demilec attic job yourself. Cut a small test cube, measure thickness, look for gaps. That’s worth doing before you spend money. What you shouldn’t do is buy a DIY spray foam kit and try to re-spray or patch a failing Demilec installation. Applying two-component polyurethane foam requires proper ratio mixing, surface temperature management, and respirator-grade PPE. Get the ratio wrong and the foam never cures properly; get it on your skin and it’s a medical visit. The Austin summer heat makes everything harder, too: foam sprayed onto a 140-degree roof deck behaves differently than foam sprayed at 70 degrees.

Tell me your square footage and I’ll give you a real number, no runaround. Call us at (361) 321-0817 and we’ll walk through what you’re seeing, what it means, and what the fix costs.

FAQs