Rayson SealForce WB20

No. It is a one-part membrane applied directly to a sound, clean, dry concrete or rendered substrate — there is no separate primer in the system. Preparation does the primer's job: remove loose material, curing compounds and protrusions, and let old concrete dry fully after washing.

At least two coats at 0.4 mm wet film each, rolled or brushed straight from the pail, the second 1–2 hours after the first. Add a third coat where the film is uneven or pinholes remain. A 20 kg pail covers about 36 m² per coat.

Only after the ponding test, 24 hours after the final coat, has proved the membrane — and always through the screed, render or tile bed that protects it. The membrane is not a wearing surface and must never be left exposed.

WB20 is a one-part, water-based membrane for concealed wet areas — toilets, bathrooms and balconies beneath tiles — chosen for ease of use and low odour in occupied homes. RC30 is a two-component polyurea-based membrane with higher elongation and heat resistance for decks, roofs and heavier-duty wet areas.

No. SealForce WB20 is a positive-side membrane and must not be used where negative hydrostatic pressure is evident, such as a basement wall with groundwater behind it. Those conditions need a tanking or crystalline system designed for them.

Each coat is touch dry in under 60 minutes at laboratory conditions; the second coat goes on 1–2 hours after the first and is dry in about 4 hours. The flood (ponding) test is carried out 24 hours after the final coat, with light foot traffic only, and the screed or tile bed follows once the test has held. In a typical HDB toilet the membrane is one day of work and the test the next.

No. It is a concealed membrane applied to the prepared screed or concrete beneath the tiles, not a coating over them. If the bathroom has failed an HDB or HIP water test, water is already under the tiles and no surface-applied product reaches the failed detail: the tiles come up, the substrate is prepared, and WB20 is applied in two coats and flood-tested before re-tiling. The wet-area guide sets out when a no-hack repair is honest and when it is not.

The product by name — Rayson SealForce WB20 — two coats at 0.4 mm wet film each (about 0.56 kg/m² per coat), the turn-up height on every wall and at the door threshold, the detailing at the floor trap, pipe penetrations and wall–floor junction, a 24-hour flood test before tiling, and who carries which warranty: the applicator for workmanship, Rayson for the material, three years against manufacturing defects when applied per the TDS. A quotation that says only "waterproofing" cannot be compared with another.

About 8 to 12 kg for two coats over a typical 3 m² toilet floor with 300 mm turn-ups and a shower wall taken to 1.8 m — under one 20 kg pail, which covers about 18 m² at two coats. Detailing, a third coat on thin patches and wastage set the actual figure; the coverage calculator gives the theoretical quantity for any area.

Rayson does not publish a service-life figure for a concealed membrane: the tile bed protects the film, and it is the details that fail, not the field. What the data shows is retention — at least 1.0 N/mm² tensile strength and 120% elongation after ageing at 50 °C and after 72 hours in hypochlorite, ammonia or dilute acid. A bathroom lasts as long as its trap, penetrations and turn-ups were done correctly and flood-tested before the tiles went down.

SealForce WB20 is part of Rayson's upcoming waterproofing release, and a pre-launch trial batch has already been applied and flood-tested in a Singapore HDB toilet. Send the project details and your required date, and Rayson will confirm supply timing, quantities and, where you need one, an applicator in the Rayson network before you commit.