Demilec Attic Insulation Nationwide

Demilec Attic Insulation: The Tustin Owner’s Guide

Demilec attic insulation replacement in Tustin typically runs $2.80-$4.20 per square foot installed for open-cell spray foam, with most single-family attic jobs falling between $3,200 and $5,800 depending on thickness and conditioned square footage. We stock Demilec Heatlok HFO High Lift and Demilec Sealection 500 on our Tustin trucks, and we can usually inspect and quote same-day. Most Tustin homeowners realize their Demilec insulation is compromised when they notice hot second-floor rooms in July, unexplained spikes in their SCE bill, or find crumbling, off-gassing foam near recessed cans in thirty-year-old attics around Tustin Legacy.

Call (657) 286-7673

Which Demilec Models This Applies To

Demilec’s two primary residential spray foam lines installed in Tustin attics are Heatlok HFO High Lift and Sealection 500. Heatlok HFO is the newer formulation, blown with hydrofluoroolefin rather than HFC blowing agents, and it’s what you’ll find in most 2018-and-newer Tustin builds, especially the infill homes north of Irvine Boulevard. Sealection 500 is the legacy closed-cell product, common in Tustin Ranch and the older condo conversions off Jamboree Road.

Identifying your product takes two steps. First, check the exposed foam at an attic hatch or penetration for a stamped lot number, usually on the cured surface or on a leftover tag the original installer left behind. Second, measure the cured thickness: Heatlok HFO High Lift is typically installed at 5.5 inches for R-38 in attics, while Sealection 500 in Tustin attics was often spec’d at 3 inches for R-19 and paired with batt insulation. The compatibility gotcha: Heatlok HFO and Sealection 500 cannot be layered directly over one another without a mechanical separation or full removal. We’ve found three Tustin attics where a handyman tried it, and the delamination showed up on thermal imaging within eight months.

We source Demilec products through authorized distribution, but we also carry Johns Manville Corbond III and Icynene MD-R-200 as quality equivalents when Demilec lead times stretch out. Topside Attic Insulation Tustin is an independent service provider, not affiliated with Demilec.

Signs Your Demilec Attic Insulation Is Failing

• Uneven room temperatures upstairs. The Tustin afternoon sun pushes attic ducts past 140 degrees; if your Demilec has settled or pulled away from the roof deck, conditioned air leaks into the attic before it reaches the bedroom registers. We measure this with a blower-door test - pressurizing the house to 50 pascals to read CFM50, the cubic feet per minute of air leakage.
• SCE bills climbing 20% or more year-over-year with no rate change. Demilec foam that has absorbed moisture or degraded loses its R-value and lets heat conduct through the attic floor. In Tustin’s inland climate, that delta between attic and conditioned space is sharper than coastal OC, so the penalty shows up faster.
• Visible crumbling, yellowing, or powdery residue on foam surfaces. UV exposure through gable vents or degradation from incompatible paint or sealant causes Demilec open-cell to break down. We’ve pulled failed batches in Tustin Legacy homes where the original installer left foam exposed to attic ventilation.
• Musty or chemical odors after the HVAC cycles. Off-gassing from degraded Demilec, or more commonly moisture trapped between failing foam and the roof deck, breeds mold in Tustin’s spring humidity spikes. The smell hits when the air handler pressurizes the duct system.
• Thermal imaging shows hot spots at the roof deck in summer. A properly installed Demilec layer should read within 5 degrees of indoor temperature at the interior foam surface. When we scan Tustin attics and see 95-degree readings at the foam face in July, the envelope has failed.

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Replacement Cost & What’s Included

Most Demilec attic insulation replacements in Tustin fall between $3,200 and $5,800 for a typical 1,600-2,400 square foot home, with smaller condo attics starting around $2,400 and larger Tustin Ranch estates with complex rooflines running to $7,500. That range covers removal of failed foam, surface prep, air sealing of top plates and penetrations, and installation of new Demilec or equivalent spray foam to current code.

What drives the number: attic square footage, roof pitch (steeper means more surface area and harder access), whether the old foam needs full removal or spot repair, and whether we find unsealed can lights or open soffits that need addressing first. We don’t blow new insulation over unsealed air leaks. Under Haven Standard Clause 1, you get a written price before any work starts, a written scope, and a written warranty. Every job closes with a Documented Photo Record and, on applicable work, before-and-after blower-door numbers so you can verify the air-sealing result. The 365-Day Done Right Promise applies to all completed work.

DIY or Call Us?

There’s no safe DIY path for spray foam insulation replacement. Demilec application requires two-component heated equipment, respiratory protection rated for isocyanates, and precise substrate temperature control. The chemicals are reactive; off-ratio mixing or application onto a cold surface in a Tustin January morning produces foam that looks right but fails in six months. We’ve been called to fix three owner-attempted jobs in the past two years.

What you can safely check: confirm your attic hatch is weatherstripped, look for daylight through soffits or around chimney chases, and note any water staining on the roof deck. Document what you find with photos. Then call us at (657) 286-7673. We’ll bring a thermal camera and blower door, read your attic, and give you a written price before any work starts. Free Second Opinion on any written estimate - bring us a competing quote and we’ll read it with you.

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