It allows for movement in the tile.
Ceramic tile expansion joint spacing.
If the ceramic tile floor is wider or longer than 25 feet you will need to install an expansion joint near the center of the floor.
Twelve inch tiles typically have at least 3 16 to as much as 5 16 inch spacing between pieces.
If you tile over an expansion joint then you need to honor that joint in the tile as well.
The tile council of north america and accompanying tile organizations recommend an average grout joint width of 3 16 inch for every 1 16 inch variation in the size of the tiles.
Where should movement joints be placed.
Install the caulk after the tiles have been set and before the grout is installed.
The as 3958 1 australian standard guide to the installation of ceramic tiles section 5 4 5 1 cautions that.
The theory is to create tile fields large enough to absorb differential movement between the substrate and the ceramic or stone covering movement joints must be installed in certain areas and positions to prevent tiles or grout from cracking and in some cases prevent the tiles from tenting and becoming debonded from the substrate.
Locate openings for expansion joints directly over cold joints and structural joints.
The tcna handbook recommends allowing for expansion and contraction in every tile installation.
Clearly grout joints also accommodate both changes in the thickness and profile of rustic hand molded tile.
Caulk the grout gap between two adjacent rows of tile all the way across the floor.
Ceramic porcelain and stone tile expands and contracts with thermal and moisture changes in the environment.
As the plane of the tile changes the grout joint allows for this change.
For example 12 inch tiles varying 1 8 inch piece to piece need a larger grout joint than perfectly consistent material.
Recognizing that tile is a facade movement joints are needed to eliminate stresses that can occur between the substrate and the tile due to differing amounts of expansion and contraction.
It is essential that the movement joints be carried through the tile and the bedding.
Expansion of the substrate due to ingress of moisture like shrinkage any change of moisture content will result in a change of shape and size ultimately leading to movement with similar consequences.
A movement joint is in the tile only.
Learn all about expansion joints here.
When tile follows a depression in the floor the grout joint will narrow.
In large areas expansion joints will be necessary for the concrete itself for all the same reasons as are needed for wall and floor tiles.
Also some 12 inch tiles have a nub on the backside of the tile determining the spacing.
For example if you take two 12 inch tiles and compare them side to side and there is a variation of 1 16 inch in the two tiles you are recommended to use at least a 3.
