VAPOR BAN Primer W is a one-part liquid membrane that does two jobs at once: it controls the moisture vapor emission rate of a concrete slab up to 100% relative humidity, and it primes the slab for an NXT Level or SUPERCAP self-levelling underlayment. Two steps in one, with no separate preparation stage.
Unlike VAPOR BAN Primer ER, this is a water-based, epoxy-free formula: ready to use, no part A and part B to mix, low VOC, low odour and non-flammable. It is hypoallergenic, which makes it a safer option for installers sensitive to resins.
The product changes colour as it cures, from light grey to light brown or beige: that is the visual cue telling you a coat is ready for the next one.
Benefits
- Vapor barrier and primer in a single product, with no separate preparation step
- Reduces MVER from 25 lbs or less to below 3 lbs/1,000 ft²/24 hrs (170 µg/(s·m²)), at 100% RH per ASTM F2170
- Ready to use: no resin mixing
- Low VOC (96 g/L), low odour, non-flammable
- Resealable, reusable packaging
- Colour change on cure as an installation cue
Coverage
Applied in two coats of 8 to 10 wet mils each. Average coverage for both coats is 88 to 100 sq ft (8.2 to 9.3 m²) per gallon, roughly 440 to 500 sq ft per 5 gal pail. Actual coverage varies with the concrete surface profile (CSP), applied thickness and slab absorption: check thickness with a wet film gauge.
Suitable substrates
Concrete, oriented strand board (OSB) and exterior-glue plywood. Concrete must be cured at least 5 days at 21 °C (70 °F), show a tensile strength of at least 200 psi (ASTM C1583) and a surface profile of CSP 1 to 3 achieved by diamond grinding or shot blasting. Interior use only.
Installation
Keep the pail between 18 and 30 °C (65 to 85 °F) for 24 hours before use. Mix for 2 minutes with a paddle mixer at low speed (300 RPM) until fully uniform. Apply the first coat with a 3/8 in. (9 mm) short-nap roller, cross-rolling at 90 degrees, then the second once the first has cured: allow 1 to 2 hours per coat. Surface temperature must stay between 10 and 32 °C (50 to 90 °F) during application and for 24 hours after.
Install the self-levelling underlayment — NXT Level or SUPERCAP — or the finished flooring within 24 hours of the last coat, provided the surface is protected from traffic, dust, debris and water.
Expansion and construction joints must be carried up through the primer and the finished flooring. Do not apply over Skim Lite, and do not use as a primer for overlays.
Precautions
⚠️ This product may cause an allergic skin reaction (H317) and causes damage to the kidneys through prolonged or repeated exposure (H372). It is also harmful to aquatic life. Wear gloves and eye protection, avoid breathing vapour or spray mist, and read the safety data sheet before use.
The product is not regulated for transport (TDG, DOT, IMDG, IATA).
