Is microcement waterproof?
The sealed surface sheds water, but microcement is not a waterproofing membrane. In a bathroom or shower, Rayson SealForce WB20 goes underneath and is flood-tested before the microcement goes on.
That is the step most failed microcement bathrooms skipped. The membrane stops water reaching the screed and the room below; the IFS MicroCrete® layers and their sealer give the seamless, wipe-clean surface on top. The floor trap and the corners are detailed first, and the sealer is renewed as the system advises.
Why does microcement crack, and how is that prevented?
Most cracks come from the base, not the coating: a slab or screed that moves, cracks or was never prepared shows through a thin finish. The applicator checks and repairs the base, and the build-up is confirmed on a sample board first.
Existing cracks are opened and filled, hollow screed is cut out and relaid, and the building’s movement joints are respected rather than covered over. On floors, Rayson PrimeBond E20 primer bonds the base; in wet areas, the flexible, crack-bridging WB20 membrane sits underneath.
Can microcement go in a shower, and will it grow mould in Malaysia’s humidity?
Yes, on walls and floors, with WB20 underneath, a floor that falls to the drain so water never stands, and a sealed surface. Mould grows where water stands and air does not move, so ventilation matters as much as the finish.
Shower floors are laid to fall before any coating, the drain and the corners are detailed, and the applicator recommends a fan or a window if the room has neither. Cleaning with a mild, pH-neutral cleaner keeps the sealer intact; harsh acids and bleach are avoided.
Can microcement go over my existing tiles?
In dry rooms, over tiles that are firmly bonded, yes. The applicator taps every tile, removes hollow ones, fills the grout lines and applies a bonding primer, so the grid of the old tiles does not show through. In a shower, the SealForce WB20 membrane goes on concrete, render or screed, not on glazed tiles, so the old tiles there come up or are screeded over first.
It saves the hacking, the debris and days of noise in a condo. Where the tiles are loose, or the floor has to stay level with the next room, the applicator says so before quoting.
