Who governs the spacing of expansion joints in interior tile floors?

• A. Spacing is randomly determined by the installer.
• B. Spacing is always 24 inches on center.
• C. Spacing is determined by manufacturer recommendations and building code.
• D. Spacing is only determined by tile color.

Answer: (C)

Expansion joints in interior tile floors are placed to accommodate movement from temperature changes, humidity shifts, and substrate settling. The correct approach is to follow what the tile or mortar system manufacturer recommends and the requirements in the building code. Manufacturers specify joint locations and spacing based on how their products handle movement, adhesive systems, and grout. Building codes set minimum standards to ensure joints exist where movement is likely and to prevent cracking or debonding across larger areas. Because of that, spacing isn’t random or fixed to a single number, and it isn’t determined by color. Always use the combination of manufacturer guidelines and code requirements to determine proper joint spacing.