PC-440/440SC is a single-component, liquid-applied, moisture-cured aromatic polyurethane elastomeric waterproofing base membrane, designed for use in most areas of California to be in compliance with air quality standards. Make sure to use the correct grade of product that complies with VOC regulations.

 PC-440 and PC-440SC are single-component, liquid-applied, moisture-cured, aromatic polyurethane elastomeric base membranes designed for waterproofing applications. These materials are especially developed for use in California to meet strict air quality and VOC regulations. The system is ICC-ES evaluated and suitable for Class A/B fire-rated systems.

 This material functions as a base membrane within a waterproofing system and is typically used with a sand broadcast layer for slip resistance. For multi-coat systems, PC-440/440SC should be recoated within 48 hours. If this window is exceeded, the surface must be solvent-wiped and re-primed using Polyprime U. PC-50 accelerator may be added for faster curing. The final system may also include topcoats as recommended by Polycoat, depending on the exposure and durability requirements.

 PC-440/440SC is suitable for use over concrete, masonry, plywood, wood, and metal surfaces. It is applied in waterproofing systems, particularly for decks, balconies, and other pedestrian traffic surfaces requiring seamless protection and fire compliance.

·       Mixing: Requires thorough mechanical mixing at slow speed to avoid air entrapment.

·       Application Method: Applied using a squeegee or notched trowel; roller application is possible with caution.

·       Aggregate Finish: Optional use of 16–20 mesh washed, dry sand (minimum 6.5 Mohs hardness) at 20 lbs/100 sqft into the second coat to provide slip resistance.

·       Thickness:

o   PC-440: ~11 ± 2 mils DFT per coat

o   PC-440SC: ~14 ± 1 mils DFT per coat

·       Coverage Rate: 1 gallon per 100 sqft for both versions

·       Recoating Time: Within 48 hours; beyond that requires solvent wipe and re-prime with Polyprime U

·       Accelerated Cure Option: With PC-50, cures in 6–8 hours at 75°F and 50% RH, with recoat window reduced to 12 hours

·       Pot Life & Cure Time: Not batch-sensitive, but cure time varies with ambient conditions; standard cure ~16 hours, faster with PC-50 accelerator.

·       Environmental Limits:

o   Application Temperature: 60–95°F (15–35°C)

o   Humidity: Sensitive to both high and low extremes, which can accelerate or delay curing

·       Shelf Life: 1 year in original sealed containers

·       VOC Content:

o   PC-440: 2.01 lb/gal (240 g/L)

o   PC-440SC: 0.78 lb/gal (94 g/L)

·       UV Resistance: Not UV stable – requires UV-resistant topcoat if exposed

·       Limitations: Not for use on split slabs, buried membranes, sandwich slabs with insulation, magnesite, unvented metal pans, or non-structural lightweight concrete. A moisture vapor transmission test is required for on-grade slabs.

·       Warnings: Contains isocyanates and curative material; professional application recommended.

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