What Would Cause Ceramic Tile to Buckle Like a Fault Line?

Inadequate Substrate Layers

• One of the common causes of buckling or broken lines in tile floors is the substrate, or the subfloor materials on which the tiles are installed. Ceramic tiles need a strong, rigid subfloor. If the subfloor is lighter materials that are springy -- such as thin plywood sheets -- eventually this flexibility causes long cracks to appear in the floor.

Lack of Membranes

• There is a family of plastic membranes known as antifracture membranes that are designed to help prepare floors that are ordinarily too flexible for ceramic tile. They may not solve extreme problems with the floor, but they can make buckles and fault lines less likely.

Lack of Expansion Joints

• If the ceramic tile floor is very wide, expansion joints are necessary. Ordinary tiles and grout lines are immovable once the tile is installed. Over wide areas, however, walls and floors can slowly shift and expand. This can cause the tile to buckle over the years. Expansion joints are lines of flexible grout products put in at intervals in order to give the tile enough room to move in response to these changes. Without the expansion joints, the tile can start to crack.

Problems with Adhesion

• Tile depends heavily on its mortar or adhesive layer that bonds it with the floor beneath. If the adhesive does not bond properly to a dirty floor or if it slowly dissolves over time, the tile can lose structural integrity. The result is tile that can slip and move, rubbing against grout lines and eventually cracking along the weakest points of the floor.