Expansion Joints - Why?

Why are Expansion Joints needed

in Tile and Stone Installations?

The basic answer is that in the construction world everything moves. Therefore, accommodation for this movement is required to prevent materials from falling apart and causing destructive failure.

This principle is no different when it comes to ceramic tile and stone installations. Movement is a natural part of these installations and must be accounted for and accommodated. There have been many industry related articles written on this topic that can be consulted for additional information. In addition, the Australian Standard AS3958.1 & 2 and Tile Council of North America (TCNA) have a very detailed explanation of the requirements and necessity for expansion joint construct, design and placement. Consult these documents for this vital information.

It is the Project Designer/Project Architect/Project Engineer’s responsibility to detail and outline the requirements for each specific project. Design Professionals have available to them tables that outline the expansion rates (coefficient of expansion) of most building materials. In their calculations, they can predict how much movement will take place on a given project over a specific substrate using a specific type of adhesive and installation method. As you can imagine, there are countless combinations. There is no way that an tiler can know which combination is applicable before they walk onto a project.

In the absence of a design professional, guidance can be sought from: AS3958.2 Section 4.5 Detailing of Movement Joints; AS3958.1 Section 5.4.5 Movement Joints; and the TCNA suggestions outlined in detail EJ-171 in the Handbook for Ceramic Tile installation. It is interesting to note that the Stone Industry also refers to these details. The ASAA Natural Stone Design Manual references the Australian Standards AS3958 and the TCNA for expansion joint requirements in stone installations. 

For more details go to: http://www.laticrete.com/portals/0/tds/tds252.pdf