GAF Bathroom Remodeling Nationwide

GAF Bathroom Remodeling: The Campbell Owner’s Guide

GAF bathroom remodeling in Campbell typically runs $9,000-$28,000 for a full renovation, with smaller projects starting around $5,000. We stock GAF-compatible waterproofing membranes, underlayment, and ventilation components, and we carry the full line of GAF WeatherStopper and StormGuard products on our trucks for same-day installation when a moisture barrier has failed. Most Campbell homeowners discover the problem when they peel back tile and find the original builder-grade paper has turned to pulp, or when a bathroom fan duct terminates in the attic and GAF’s Cobra ridge vent system is pulling that wet air back through the roof deck.

Call (831) 704-1211

Which GAF Models This Applies To

GAF does not manufacture bathroom fixtures. What we install are GAF roofing and waterproofing products adapted for vertical and wet-zone applications: StormGuard leak barriers (self-adhering membrane, 40 mil), WeatherWatch ice and water shield (used as shower pan liner backup in some Campbell retrofits), and Cobra and Master Flow ventilation components. The critical compatibility issue is membrane thickness versus substrate prep. StormGuard bonds aggressively to OSB but requires a primer on old plaster, which we see in Campbell’s 1950s ranch stock near the Pruneyard. WeatherWatch is 36 inches wide, so a standard 36-by-60-inch shower pan takes one horizontal run plus a seam, not two runs. We source factory-direct GAF membrane; aftermarket equivalents exist (Grace, Henry) but we spec GAF when the roof and bathroom are being done together because the warranty language cross-references. Check the roll label: GAF prints lot numbers and thickness specs in 2-point type on the release liner edge.

Signs Your GAF Bathroom Remodeling Is Failing

• Soft drywall corners near the tub. This means the leak barrier behind the tile did not extend to the tub flange, or the GAF membrane was cut short at the corner. Water follows the path of least resistance and pools there first.
• Musty attic air pulled into living space. When a bathroom fan duct is disconnected or terminates in the attic, GAF’s Cobra ridge vent can create negative pressure that draws moist air down through can lights. We find this in Campbell’s tighter 1990s builds with aggressive attic ventilation.
• Tile cracking in a straight line. The substrate moved. If GAF StormGuard was applied over uncured thinset or green drywall, the membrane bonds but the substrate shrinks, telegraphing cracks through the tile.
• Grout turning dark at the shower curb. The pan liner failed or the leak barrier did not overlap the curb. GAF membrane at 40 mil will outlast PVC liner if installed correctly, but the overlap order matters: liner first, then membrane, then pre-slope.
• Paint bubbling on the ceiling below a second-floor bath. This is usually a vent boot failure where GAF Master Flow ducting meets the roof deck, or a leak barrier that stopped at the subfloor instead of wrapping to the underside.

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Replacement Cost & What’s Included

The range depends on three things: whether we hit original 1950s galvanized plumbing that needs full replacement, whether the subfloor is rotted and needs sistering, and tile selection. A $9,000 job uses standard ceramic and a single GAF membrane layer; a $28,000 job runs natural stone, heated floors, and full GAF StormGuard plus WeatherWatch redundancy in the wet zone. Under Clause 1 of the Haven Standard, the written price covers everything in the scope. No change proceeds without a signed change order, which is why our projects finish within a few percent of the agreed number. The 365-Day Done Right Promise covers workmanship; GAF’s material warranty runs 10-20 years depending on product line.

DIY or Call Us?

There is safe checking and there is unsafe work. A homeowner can verify the bathroom fan duct actually reaches the roof jack, or confirm whether GAF membrane is visible at the tub flange edge by removing an access panel. What we do not recommend: peeling back tile to inspect membrane adhesion, cutting into a shower pan to check liner overlap, or working in the attic near active electrical while checking vent boots. Campbell’s older homes near downtown have knob-and-tube splices in attic spaces that are not obvious until you’re inches away. We carry GAF StormGuard and WeatherWatch on every bathroom truck, and we document the substrate condition with photos before we cover it. If you want to know what failed before committing to a full scope, we offer a documented inspection with a written finding - not a sales pitch. Call (831) 704-1211 to schedule.

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