1.Why tiles will move?
Tile will expand when it is subjected to any kind of moisture – water or even humidity – or when it is subjected to heat. Tile will contract when it dries or cools. There are also dynamic structural movements that tiles are subjected to that cause them to move. Each day tile installations constantly go through expansion, contraction and dynamic movement cycles, and that''s why it''s so important to design them with expansion/ movement joints.
2.The result of tiles move without movement joints
Expansion and contraction cycles cause stress to tile assemblies that can result in a number of different problems.
2.1 If the tiles are well bonded, but lack expansion joints, then the problem might manifest as cracking in the tile or grout.
2.2 Without enough room for the tile assembly to expand, the tile will pop up or "tent" most times in the middle of the floor.
Cracks in interior wet or exterior areas can cause moisture migration that can cause additional damages to adjacent materials.
So in general,when tile installation failures occur, the lack of movement joints is a contributing factor to many types of failures.
3.How to install tiles movement joints in tiles installation
So in ceramic, porcelain, glass and stone tile installations,Movement Joints also known as Movement Accommodation Joints are critical to the success and longevity of the installation.
Movement joints are to be installed every 20CM to 30CM for exterior areas, or interior areas where tile work is exposed to direct sunlight or moisture, or for above-ground concrete slabs. For interior areas the standard is every 50CM to 64CM.
In addition, all tile perimeter and transition areas should have movement joints. That includes all floor and wall applications.