Florida Tile lists our unglazed tiles with a P1 rating for abrasion resistance. This has caused some confusion in the market since the P1 rating is a bit hard to understand. Explanation is below, but all Florida Tile products marked with a P1 rating are considered Heavy Commercial products from an abrasion resistance standpoint.
Abrasion resistance for glazed tiles is summarized in ANSI® A137.1 with a convenient table that rates the products from Class 0 ‘not recommended for floors’ to Class V ‘heavy commercial’ based on a test that simulates foot traffic and looks for scratches in the glaze.
Unfortunately, ANSI® does not rate unglazed products in the same way. Instead, unglazed products are tested with a grinding wheel and the amount of material removed in a set amount of tile is measured. The less material removed, the harder the tile. In the past, instead of listing a rating we simply listed the amount of material removed with the test. We decided for accuracy to ANSI® A137.1 to list the “P1” value but that has raised some questions from our customers.
A P1 tile is pressed (P for pressed), impervious (<0.5% absorption), and has had less than 175 cubic millimeters of surface removed by the grinding wheel when tested according to ASTM® C1243. What this means practically is that the tile extremely resistant to wear and stains. A Florida Tile P1 tile will show very little to no wear even when subjected to heavy traffic with very abrasive soil. An example of this would be the floor of a manufacturing facility.*
The Tile Council of North America and tile manufacturers are working on a better testing method and rating scale that can be used for both glazed and unglazed tiles in the same way. Since this new rating scale it not yet ready, we are resigned to using the ratings currently spelled out in ANSI®.
*Please note that a P1 rating is not the only characteristic of a tile to review when determining suitability of a tile for a particular application. Coefficient of Friction, for example, must also be taken into consideration.