Allowable Deflection For Ceramic Tile

All structural members will deflect or flex under load.

Allowable deflection for ceramic tile.

For soft stone tile such as limestone or light marble the l 720 formula applies cutting the maximum allowable deflection in half. Traditionally the accepted minimum requirement for floor rigidity is l 360 before the tile underlayment is installed. The l 360 formula is useful for most ceramic porcelain and hard stone. John bridge forum also offers this helpful deflection calculator.

For natural stone tile installations maximum allowable floor member. Whether you are installing stone or ceramic tile over floors and walls there s one thing to consider. Allowable deflection is generally expressed as a fraction of the span in inches. What is the acceptable deflection for a floor that will be tiled.

For example the allowable deflection of a 12ft span floor joist with plaster l 360 is 0 4 12ft divided by 360. Maximum allowable deflection for substrates. The marble institute of america recommends that total load deflection be limited to l 720 for spans up to 14 0 and a maximum deflection of 7 32 for spans greater than 14 0. Live load deflection less than l 360 for l about 8 ft l 480 for longer spans.

The l 360 standard means that the floor should not deflect more than the span divided by 360. Learn more about it here. The tile council of america recommends that deflection be limited to l 360 l span length in inches under total load for ceramic tile. For ceramic tile installations maximum allowable floor member live load concentrated load impact load and dead load shall not exceed l 360 where l is the clear span length of the supporting member per applicable building code.