Thinset Over Painted Floor

Cracks and gaps can be filled with portland cement based fillers.

Thinset over painted floor.

The floor is a 4 inch poured concrete slab over an unheated utility room. Paint used on concrete will not bond with the tile adhesive. Tile adhesive is expected to hold the tile in place not just for years but for decades without fail. A scratch coat will give the mortar something to hold on to instead of the layer of paint over concrete.

Mortar cannot be installed directly over painted concrete itself. Whether you have cracks chips or just a stained concrete slab thinset helps cover the old surface and create a new problem free area. It cannot cure too fast. Unfortunately the tile cannot be adhered directly to the painted surface.

Tile will stick to most rigid level surfaces including painted wood provided the correct preparation work is done to ensure the adhesive or mortar will stick to the floor surface. It must be easy to work with and it must adequately fill in gaps between the tile and the substrate. Otherwise you do. Tile cannot be attached directly to painted concrete as the thin set will not adhere well to the paint.

The house was built in the late fifties and the slab floor has been painted at least once. How to use thinset morter to resurface concrete. First a surface more textured and solid must be applied over the painted concrete. Installing tile over painted concrete adds a few extra steps to your tiling job.

Not that they would endorse going over an oil based paint what you should do is scarify the paint off the floor. All paint will need to be removed before you begin installing the tile. This surface is called a scratch coat. The safest way to approach questionable concrete is not to cover it over with cbus but to fix the concrete.