Thinset Over Painted Floor

The house was built in the late fifties and the slab floor has been painted at least once.

Thinset over painted floor.

Thinset mortar is your default tile mortar for most indoor and outdoor applications. The thin mix is laid over. Thinset is a mortar that is made of portland cement silica sand and moisture retaining agents. Mortar cannot be installed directly over painted concrete itself.

A latex based thin set adhesive should be used over the latex based paint. If the paint is not well attached then as the thin set adhesive dries and shrinks it might pull the paint loose. A scratch coat will give the mortar something to hold on to instead of the layer of paint over concrete. This will seal the wood and create a matte finish that will adhere to the tile well and help to stabilize the.

Thinset tile mortar has a smooth slippery consistency similar to mud. It is applied to the substrate with a notched trowel. The painted surface has to be cleaned properly to ensure an adequate bond. This surface is called a scratch coat.

Whether you have cracks chips or just a stained concrete slab thinset helps cover the old surface and create a new problem free area. First a surface more textured and solid must be applied over the painted concrete. Only use epoxy and latex thin set products that state they can be used for bonding tile to paint. Apply a coat of sanding sealer or tile prep sealer to the floor with a paint roller.

The floor is a 4 inch poured concrete slab over an unheated utility room. All paint will need to be removed before you begin installing the tile.