It is best to achieve a two sided bond only to the flanks of the open joint in the tile.
Tile expansion joint detail.
An expansion joint is in the substrate for instance in concrete.
Movement joints are an integral part of any tile assembly and must be incorporated within the tile field at doorsills and at transitions to walls and other restraining structures to allow movement of the assembly and prevent stresses that can damage the system.
Possibly the best type of expansion joint material that can be used is a flexible silicone e g.
The tcna handbook recommends allowing for expansion and contraction in every tile installation.
Where should movement joints be placed.
It s quite common to see controlled breaks in concrete and those are usually expansion joints.
As the concrete cures it generally shrinks.
The sealant used in expansion joints should achieve a minimum shore a hardness of 35.
It allows for movement in the tile.
Joints in the tile assembly will result in callbacks and expensive repairs as well as the subsequent installation of movement joints.
Expansion joints are created in the concrete to compensate for excessive expansion due primarily to temperature changes in the concrete.
Latasil or urethane sealant placed over a closed cell foam backer rod.
If you tile over an expansion joint then you need to honor that joint in the tile as well.
A movement joint is in the tile only.