For example 12 inch tiles varying 1 8 inch piece to piece need a larger grout joint than perfectly consistent material.
Ceramic tile expansion joint spacing.
Twelve inch tiles typically have at least 3 16 to as much as 5 16 inch spacing between pieces.
Caulk the grout gap between two adjacent rows of tile all the way across the floor.
It allows for movement in the tile.
Should tile go over a hump in the floor the grout joint will open.
Also some 12 inch tiles have a nub on the backside of the tile determining the spacing.
A movement joint is in the tile only.
Clearly grout joints also accommodate both changes in the thickness and profile of rustic hand molded tile.
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.
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.
Locate openings for expansion joints directly over cold joints and structural joints.
Learn all about expansion joints here.
If you tile over an expansion joint then you need to honor that joint in the tile as well.
It s quite common to see controlled breaks in concrete and those are usually expansion joints.
Where should movement joints be placed.
As the plane of the tile changes the grout joint allows for this change.
It is essential that the movement joints be carried through the tile and the bedding.
Ceramic porcelain and stone tile expands and contracts with thermal and moisture changes in the environment.
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.
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.
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.
When tile follows a depression in the floor the grout joint will narrow.
An expansion joint is in the substrate for instance in concrete.
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.
Install the caulk after the tiles have been set and before the grout is installed.