Demilec Radiant Barrier Installation Nationwide

Demilec Radiant Barrier Installation: The Long Beach Owner’s Guide

Demilec radiant barrier installation in Long Beach typically runs $1,800-$3,400 for a complete attic application, and most jobs can be scheduled within 48 hours. We stock Demilec-compatible radiant barrier materials on our trucks, including Heatlok HFO and Demilec APX series-compatible reflective assemblies, so we’re not waiting on a distributor run to Seal Beach. Most Long Beach homeowners realize their radiant barrier is compromised when upstairs rooms stay hot past 7 p.m. even with the AC running, or when they spot sagging, torn, or dust-coated reflective sheets during an attic storage trip.

Call (424) 415-7031

Which Demilec Models This Applies To

Demilec doesn’t manufacture standalone radiant barrier products; instead, they produce spray foam and hybrid insulation systems designed to integrate with third-party radiant barrier assemblies. The two Demilec product lines we encounter most in Long Beach attics are Heatlok HFO (closed-cell spray foam, often used in combination with radiant barriers in conditioned attic assemblies) and Demilec APX (open-cell foam, common in 2018-2023 new construction from Naples down to Belmont Shore).

To identify what you’re working with, check the spray foam label on your roof deck or gable ends. Heatlok HFO will show a yellow-tinted foam with a printed lot number; APX is white to cream-colored. The critical compatibility gotcha: Demilec’s HFO formulation requires a Class A fire-rated radiant barrier when installed within 18 inches of the foam surface per California Title 24. We’ve found builders in the Wrigley area who used unrated reflective sheathing to save $0.12 per square foot, and that assembly fails inspection on resale.

For OEM-spec replacement, we source Demilec-compatible radiant barrier from the same distributors who supply the foam: IDI, L&W Supply, or direct from Demilec’s Ontario warehouse. Aftermarket equivalents from Reflectix meet the same emissivity spec (0.05 or lower) at roughly 15% less cost, though we always verify the ASTM C1313 certification before installation. Measure first, then insulate - otherwise you’re just trapping the problem.

Signs Your Demilec Radiant Barrier Installation Is Failing

• Hot second-floor ceilings past sunset. A functioning radiant barrier reflects 95% of radiant heat back toward the roof deck. When the reflective surface oxidizes or collects a layer of attic dust, emissivity climbs above 0.10 and heat starts migrating downward into conditioned space. In Long Beach’s marine layer cycle, that dust accumulation happens faster than inland - we’ve measured 40% performance loss in 7-year-old installations near the port.
• Tears or sagging between rafters. Demilec-integrated radiant barriers are often stapled to the underside of roof decking before foam application. If the staple pattern was too sparse or the wrong crown width was used, gravity and thermal cycling pull the sheet loose. Once it sags, it stops reflecting effectively and can block soffit ventilation paths.
• Visible mold on the reflective surface. This indicates a moisture drive problem, usually from an unsealed attic floor below the radiant barrier. The barrier didn’t fail; the air sealing did. We see this in 1940s California bungalows in Bixby Knolls where previous contractors blew insulation over leaky top plates and called it done.
• Uneven performance room-to-room. If your master bedroom stays hot but the hallway cools normally, the radiant barrier was likely installed in sections with gaps at valleys or dormers. Demilec foam systems require continuous radiant barrier coverage to achieve their rated assembly R-value; any break creates a thermal bypass.
• Energy bills climbing year-over-year with no rate change. A degraded radiant barrier forces your HVAC to run longer cooling cycles. We’ve pulled utility bills for Long Beach clients and correlated 18-22% summer kWh increases with radiant barrier failures at the 8-12 year mark, especially in homes within a mile of the ocean where salt air accelerates surface oxidation.

Replacement Cost & What’s Included

In Long Beach, a full Demilec-compatible radiant barrier replacement typically falls between $1,800 and $3,400 installed. Here’s how that breaks:

The wide range comes down to three factors: attic square footage, whether we need to remove degraded existing material first, and how much air sealing the floor needs before the new barrier goes in. A 1,200 sq ft ranch in Los Altos with clean access runs toward the lower end; a 2,400 sq ft two-story in Belmont Heights with cathedral ceilings, recessed lighting, and rodent-damaged old barrier pushes the upper bound. Every job gets a written price before any work starts - Haven Standard Clause 1 - and the 365-Day Done Right Promise covers the full assembly.

DIY or Call Us?

There’s a short list of what a homeowner can safely verify without calling us. Check your attic hatch for visible sagging or tears. Note any hot spots with an infrared thermometer on a sunny afternoon. Read your Demilec foam lot label if you can reach it safely.

Here’s where DIY goes wrong. Working in a Long Beach attic in August is genuinely dangerous - heat exhaustion sets in faster than most people expect, and 1920s rafter spacing wasn’t designed for modern body dimensions. More critically, disturbing a Demilec-integrated radiant barrier without understanding the foam interface can compromise the fire rating or create an air leak path that voids the original insulation’s performance. We don’t recommend homeowners staple, cut, or remove radiant barrier material themselves.

If your upstairs is running hot and the attic looks questionable, call (424) 415-7031. We’ll read your existing setup, measure the actual performance gap, and give you a written price before anyone lifts a tool.

FAQs