Can Painted Concrete Floors Be Tiled?

Painted Concrete

• Do not lay tile directly on painted concrete floors without proper preparation. The paint is only a thin surface layer on top of the concrete. Although it may be adhered to the concrete when installing the tile, over time it can loosen and begin to peel away from the concrete. This in turn causes the tile to pull away from the concrete as well. In order for the tile to stay in place permanently, lay it directly on the concrete, without the paint in between.

Chemical Removal

• Remove paint from concrete by using chemicals. Chemical removal is less labor intensive than scraping or grinding away the paint. The problem with chemical removal is that the chemicals used to remove the paint can seep into the concrete. The mortar adhering tile to the concrete may react with the chemicals used to strip the paint. The mortar could break down or loosen, causing the tiles to come loose and creating the same problem as if the paint were still in place.

Mechanical Removal

• For placing tile on concrete covered with paint, mechanical paint removal is the best choice. This can be time and labor intensive, but it ensures that the tile will not come loose and will remain in place for many years. Scraping is the most common way to remove paint from concrete floors. Shot blasting will also remove paint, but can be expensive. The shot blasting process is similar to sand blasting, but uses small metal beads instead of sand. A grinder can also remove paint from concrete, but don’t gouge or damage the surface.

Subfloor

• If removing the paint from the concrete is not an option, place a plywood subfloor on top of the concrete and then install the tile atop the plywood. A subfloor can also solve a lot of other problems, such as covering cracks, seams and high or low spots in the concrete. On the other hand, it can create some other problems by raising the height of the floor. This may require shaving the bottoms of doors that open into the room and making adjustments between floors that abut the plywood-covered floor.