Floor Tile Deflection Normal

Calculating deflection many tile contractors can judge a floor s deflection by walking around.

Floor tile deflection normal.

The american national standard specifications for installation of ceramic tile ansi a108 states total load deflection not the code minimum total load deflection of l 240 criterion should be l 360. Normally this is avoided if when the wood subfloor underlayment is installed it is glued and screwed so there isn t any movement or chance for there. In this test floor tiles are run through a machine that exerts loads on an unsupported 1 inch square area. Depending on a number of factors if you have a floor that spans 10 feet in length then a defection of a 1 4 or 1 3 of an inch might be acceptable.

Answer answer the fact that there is a squeak under the tile suggests that the wood underlayment subfloor is moving to some degree. Adding plywood cuts deflection by about 80 percent. Recent research has shown tile to fail under some conditions when the floor is more rigid than l 360. The asce defines the deflection ratio as the maximum distance from a straight line drawn between 2 points on a foundation and the surface of a foundation.

As long as the tile does not break under 250 pounds of pressure the tile is considered to be compliant with these standards. The adhesive bond that secures the tiles the setting bed on which the tiles are installed the structure that holds everything up and a grid of flexible movement joints that help isolate the installation from normal expected structural movement. For instance ceramic tile can withstand more deflection than natural stone. When applied the standard taken in isolation can mean that slopes in excess of 1 inch over a 15 foot span are acceptable.

Ansi a108 section an 2 3 deflection. I doubt that it is the tile assembly itself moving independent of the floor but that would have to be verified. Most tiles meet the 250 pound minimum. A low tone is not a cause for immediate panic however.

The long term success of any tile floor installation depends on a number of factors. It makes the floor stiff without creating obstructions in the basement but it s more expensive 8 to 12 per joist than other methods and won t work if you have plumbing or electrical lines mounted to the underside of the joists. In fact failures at l 600 have been observed. Prepping wood framed floors for tile.

Floor areas over which tile is directly bonded to subfloor shall not have a deflection greater than. Most tiles comply with astm c648 breaking strength standards. It is for this reason that recommendations for floor rigidity are not based on deflection measurements but on empirically established methods found to work over normal code construction.