Demilec Attic Insulation: The Dallas Owner’s Guide
If you have Demilec spray foam in your Dallas attic and it’s failing, flaking, or pulling away from the roof deck, we can match the product, remove the bad section, and reapply a Demilec-compatible insulation for $1,800 to $4,600 depending on square footage and how much old foam has to come out first. Most Dallas jobs run two to three days from first look to finished attic, and we stock Demilec Heatlok HFO and Sealection 500 on the truck. The way most homeowners discover the problem is visual: yellowing foam, cracking along the roofline, or a utility bill that climbed 30 percent with no other explanation.
Alden Insulation Dallas is an independent insulation contractor. We install and remove Demilec products, but we’re not affiliated with Demilec. What we are is a Garrison Partners company that has been doing attic work in Dallas since 2002, with written prices and a written 365-day guarantee on every job.
Which Demilec Models This Applies To
Demilec makes two main product lines that show up in Dallas attics: Heatlok HFO, a closed-cell spray foam, and Sealection 500, an open-cell foam. The closed-cell runs about R-7 per inch and the open-cell around R-3.8 per inch. That’s a real difference when a Dallas summer pushes attic temps past 130 degrees, and it’s the first thing we check when someone calls about a failing Demilec install.
Here’s the compatibility gotcha most homeowners don’t know: you can’t patch open-cell with closed-cell, or vice versa. If your attic has Sealection 500 and someone sprays Heatlok HFO over the damaged area, the two foams cure at different rates and the bond fails within a year. The label on the existing foam will say which product it is. If the label is gone, the foam’s texture tells us: open-cell feels spongy and soft, closed-cell feels hard and rigid. Aftermarket equivalents exist, but with Demilec specifically we recommend staying with the same product line. Mixing brands inside one attic is how you end up with uneven R-value and a warranty nobody will honor.
Signs Your Demilec Attic Insulation Is Failing
- Foam pulling away from the roof deck. This usually means the original installer sprayed onto a dusty or damp surface and the foam never bonded. In Dallas, the freeze-thaw cycle between December and February makes the gap worse each year.
- Yellowing or dark amber discoloration. UV exposure breaks down spray foam over time. If you have daylight showing through a ridge vent or soffit gap, that UV is hitting the foam every day and degrading it.
- Flaking or powdering near the eaves. This is a moisture problem. Dallas humidity gets into the attic, condenses on the foam, and the foam starts shedding its top layer. Once it’s flaking, the R-value is dropping and the foam needs to come out.
- A climbing electric bill with no other change. Demilec foam loses effectiveness when it cracks or separates. If your July bill is $90 higher than last year and the HVAC is the same age, the attic is the first place we look.
- Rodent or insect activity in the foam. Rats and squirrels burrow into open-cell foam in Dallas attics, especially in older neighborhoods like Lakewood where the tree canopy gives them a highway to the roofline. Once they tunnel through, the foam’s air-sealing value is gone.
Replacement Cost & What’s Included
Here’s what Demilec attic insulation removal and replacement runs in Dallas, based on the jobs Bryce Holloway and our crew have priced across the metro:
| Job Type | Typical Dallas Price Range |
|---|---|
| Spot repair (under 200 sq ft of failing foam) | $1,800 – $2,600 |
| Partial removal and respray (200-600 sq ft) | $2,600 – $3,800 |
| Full attic removal and new Demilec install (up to 1,200 sq ft) | $3,800 – $4,600+ |
The price includes removal of the failed foam, prep of the surface, new Demilec product, and cleanup. The range depends on how much old foam has to come out, how easy the attic is to work in, and whether we need to add air sealing around the eaves and penetrations. You get the written price before any tool comes off the truck, and the whole job is covered by the 365-Day Done Right Promise. If the foam fails in that year, we come back and fix it at no charge.
DIY or Call Us?
What you can check yourself: look for obvious cracking, yellowing, or gaps where foam has pulled away from the roof deck. Take photos with your phone from the attic access. That helps when you call us, because we can tell a lot from a picture before we even come out. What you shouldn’t do is try to scrape out and respray foam yourself. Spray foam is a two-part chemical reaction that requires proper mixing equipment, respirators, and ventilation. Get the mix wrong and you get foam that never cures, or foam that off-gasses into your living space for months. Most barrel kits sold online are not the same chemistry as Demilec’s commercial products, and the result is an attic with worse performance than when you started. Call (940) 748-1726 and we’ll give you a straight answer on whether it’s a repair or a redo.
FAQs
Demilec spray foam, properly installed and protected from UV, lasts 20 to 30 years in a Dallas attic, though the Dallas heat and humidity mean open-cell foam on older homes near the Lakewood area often shows wear by year 12 to 15 if the attic ventilation was never corrected. Closed-cell Heatlok HFO typically outlasts open-cell by a decade. If your foam is under 10 years old and already failing, the install was the problem, not the product.
Small cracks and minor separations can sometimes be repaired by cutting out the damaged section and respraying with the same Demilec product, but flaking, rodent damage, or foam pulled back more than a few inches means removal and respray. The repair decision comes down to whether the remaining foam still has a solid bond to the deck. We’ll tell you which one it is before we quote anything.
Most residential Demilec removal and respray jobs in Dallas take one to two days on site. Removal of the old foam usually eats up the first day, especially in tight attics. The new foam cures in under an hour, but we hold off on final inspection until the next morning so the foam has fully settled. Call (940) 748-1726 for a timeline on your specific attic.
Yes. We keep Heatlok HFO and Sealection 500 on our Dallas trucks, which means most repairs start the same day we diagnose the problem. We also stock Reflectix radiant barrier for attics that need a hybrid approach. If your attic needs a product we don’t carry, we’ll tell you that up front and order it before we schedule the work, not after.
Get the R-value right, and the house takes care of the rest. If your Demilec attic insulation is failing, call Alden Insulation Dallas at (940) 748-1726. A live person answers, we schedule inside a real window, and the written price is in your hand before we touch the attic.
Written by Bryce Holloway, Owner, Alden Insulation Dallas at Alden Insulation Dallas, serving Dallas and nearby areas.