A tile's break strength is a numerical representation of how much weight the tile can support. Tile break strength is determined in a lab setting by the American Society for Testing and Materials. Understanding what this number means will help you determine the strength of your tile and what type of use it is appropriate for. You can take this understanding one step further by also considering the class rating of your tile. With both of these numbers in hand, you'll be prepared to evaluate your tile and determine the most appropriate plan for installation.
Acquire the break strength rating and class of the tile from the manufacturer. Tile class is a more commonly used piece of information and can usually be found on the packaging for the tile. Class is represented by a number between 0 and 5, and can also be referred to as the PEI rating. Break strength is not usually listed on the product packaging, but can often be found under the tile specifications when shopping online. Break strength is represented numerically by a number of pounds. If this information is not readily listed, contact the retailer or manufacturer for detailed information. This information should be readily available from any reputable tile manufacturer.
Evaluate the break strength rating in comparison with industry requirements. The break strength of a tile is the amount of weight that it can withstand unsupported before it breaks. The ANSI requires a break strength of at least 250 lbs. for floor tiles. If you're looking at a break strength lower than that, you can't use that tile on the floor.
Compare the class of the tile with your needs. It can be difficult to reconcile the intended use for your tile with the number that represents its break strength. The class rating provides a simpler way for laymen to understand the possible uses for a certain tile. Class 5 tile will stand up to serious wear and can be used in any situation. Class 4 is still be sturdy, and appropriate for both commercial and residential use. Class 3 tile is appropriate for light commercial and heavy residential use, such as that found in an entryway, kitchen or busy hall. Class 2 tile is the best choice for most bathroom projects because it stands up to moderate traffic. Class 1 tile is the most fragile, and should only be used in bathrooms with light, barefoot traffic and minimal dirt. Tile that is Class 0 should not be used on floors and is only appropriate on walls.