Demilec Vapor Barrier Installation: The Georgetown Owner’s Guide
Demilec vapor barrier installation in Georgetown typically runs $1,800-$3,400 for a full crawl space or attic application, depending on square footage and whether we’re sealing over bare earth or replacing a failed existing barrier. We stock Demilec-compatible 10-mil and 15-mil reinforced polyethylene on every truck, and most Georgetown jobs are completed in a single day. Homeowners usually discover the problem when their crawl space starts smelling musty in July, their floors feel cold despite good attic insulation, or they spot white mineral deposits - efflorescence - blooming on the block walls.
Which Demilec Models This Applies To
Demilec doesn’t sell vapor barrier as a standalone consumer product with model numbers like a garage door opener. Instead, you’ll find their material spec’d on the spray-foam side of jobs - particularly their Heatlok HFO Pro and Demilec 500 open-cell lines - where the vapor barrier is part of a complete envelope system. The critical compatibility question is whether your existing barrier was installed as part of a Demilec spray-foam job or added later by a different contractor.
If your vapor barrier is original to a Demilec foam installation, check for a project sticker or spray-foam tag in the rim joist area. The date and installer name tell us whether we’re matching to 2009-era 6-mil poly or a more recent 10-mil woven reinforcement. We also see plenty of Georgetown homes where a previous owner added thin 4-mil sheeting from a hardware store - that material degrades in 3-5 years in Central Texas heat and is not equivalent to what Demilec spec’d.
We carry both virgin resin reinforced polyethylene and a quality aftermarket equivalent that meets the same permeance ratings. For most Georgetown crawl spaces, the aftermarket performs identically; we only push OEM when we’re tying into an existing Demilec warranty claim. Topside Attic Insulation Georgetown is an independent service provider, not affiliated with Demilec.
Signs Your Demilec Vapor Barrier Installation Is Failing
- Musty odors rising through floor gaps. When the barrier tears or pulls away from the walls, ground moisture evaporates directly into your crawl space. In Georgetown’s clay-heavy soils around the San Gabriel River corridor, that moisture load is higher than most homeowners expect, and the smell reaches living spaces through plumbing penetrations and subfloor gaps.
- Cold floors in winter despite adequate attic insulation. A failed vapor barrier lets evaporative cooling work against your floor assembly. The air below your subfloor becomes damp and cold - sometimes 15-20 degrees below the conditioned space above - and no amount of attic R-value fixes that.
- White powder on block or poured walls. That’s efflorescence, mineral salts carried through the masonry by moisture vapor. It means water is moving through your foundation walls and hitting the air gap where your barrier should be stopping it.
- Sagging or pooling water on the barrier surface. Proper installation includes slope and drainage to a sump or daylight. When installers skip this step - common in the 2015-2019 Georgetown building boom - water collects, stretches the poly, and eventually breaches it.
- Visible tears at seams or pier wraps. Demilec-spec’d barriers should be overlapped 12 inches and sealed with pressure-sensitive tape or acoustic sealant. We regularly find shortcuts: 4-inch overlaps, no sealing, or piers wrapped like Christmas presents with a single piece that rips on the first hot day.
Before
AfterReplacement Cost & What’s Included
Most full crawl space vapor barrier replacements in Georgetown run $1,800-$3,400. The low end covers a clean, rectangular crawl under 1,200 square feet with good access and simple pier spacing. The high end reflects larger footprints, tight access requiring belly-crawling, extensive debris removal, or foundation walls that need pretreatment for mold or efflorescence before the new barrier goes down.
Our price includes removal and disposal of the old material, surface prep, installation of new 10-mil or 15-mil reinforced polyethylene with proper overlap and sealing, pier and penetration detailing, and a Documented Photo Record showing before, during, and after. We also run a quick blower-door test - a pressurization reading that shows, in one number, how much air your building envelope is losing - to flag any attic-to-crawl connections that could undermine the new barrier’s performance. Under Haven Standard Clause 1, you get a written price before any work starts, a written scope, and a written warranty. The 365-Day Done Right Promise applies to all completed work.
DIY or Call Us?
There’s no high-tension danger in vapor barrier work, but there is a expertise gap that costs homeowners money twice. What you can safely check: whether your existing barrier is torn, whether seams are sealed, whether water is pooling. What goes wrong in DIY: inadequate overlap, wrong tape that fails in crawl space humidity, missed pier detailing that channels water to the lowest point, and - most common - installing barrier over unsealed air leaks so you’re trapping moist crawl space air against your floor assembly.
We’ve re-done three Georgetown DIY jobs in the past 18 months where the homeowner spent $400 on materials and $2,200 on us to remove and replace it correctly. Seal the holes first. Then we talk about R-value. For a free written estimate with upfront pricing, call (254) 970-2136.
FAQs
How long should a Demilec vapor barrier last in Georgetown?
Properly installed 10-mil reinforced polyethylene should last 15-20 years in Central Texas, though we’ve replaced 6-mil hardware-store poly after 3-5 years in Georgetown attics that hit 140°F in August. The clay soils and seasonal moisture swings here are harder on material than the dry western suburbs. Call (254) 970-2136 if you’re unsure what you have - estimates are free.
Can a torn vapor barrier be repaired instead of replaced?
Small punctures or seam gaps can be patched with compatible tape if the surrounding material is still supple and the tear is under 6 inches. If the poly is brittle, extensively torn, or was undersized to begin with, patching is false economy - you’ll be back in the crawl space within two years. We assess this during our free estimate and tell you straight which path saves money long-term.
How long does a full replacement take?
Most Georgetown crawl spaces are completed in 4-6 hours for a standard footprint under 1,500 square feet. Tight access, debris removal, or mold pretreatment can extend that to a full day. We schedule morning starts and aim to have your crawl space closed up before afternoon heat builds - our crews have worked enough Georgetown summers to know why that matters.
Do you stock Demilec-compatible vapor barrier on your trucks?
Yes - 10-mil and 15-mil reinforced polyethylene in standard roll widths, plus seam tape, acoustic sealant, and pier wrap material. For same-day emergency replacements after water damage or pest intrusion, we can usually be on-site within hours. Call (254) 970-2136 to confirm current truck stock for your square footage.
Ready to stop the moisture problem for good? Call (254) 970-2136 for a free written estimate with upfront pricing - no work starts without a written price, and you’ll receive a Documented Photo Record and, where applicable, before-and-after blower-door numbers so you can verify the result yourself.
Written by Wes Okafor, Owner, Topside Attic Insulation Georgetown at Topside Attic Insulation Georgetown, serving Georgetown and nearby areas.