Wakulla Carpet Brokers
29 Feli Way
Crawfordville, Fl. 32327
(850) 926-8009

Tile Ratings

PEI Rating Scale

Source: The Porcelain Enamel Institute



The PEI Rating defines the wear and durability of a tile's glazed surface.

  • Class 0 - Decorative
  • Class 1 - Residential and commercial wall and bare foot traffic
  • Class 2 - Wall and residential bath floor, soft-soled traffic
  • Class 3 - All residential and light commercial floors
  • Class 4 - Medium commercial and light industrial, institutional, moderate soiling
  • Class 5 - Heavy and extra-heavy traffic, abrasive dirt

CTDA Shade Variation

Source: Ceramic Tile Distributors Association

The color shade or shades of all tile varies in some degree from piece to piece, from each production run to run. At least several pieces from the same production should be reviewed whenever possible to determine acceptable color shade variations. Any questions or concerns about your tile selection should be clarified prior to installation.

  • V1, Uniform - Minimal to no differences among pieces from the same production run.
  • V2, Slight - Distinguishable differences in texture and/or pattern within similar colors.
  • V3, Moderate - While the colors present in a single piece of tile will be indicative of the colors to be expected on other tiles, the amount of colors on each piece may vary significantly.
  • V4, Random - Random color variation from tile to tile, so that one tile may have totally different colors from that on other tiles. Thus, the final installation will be totally unique.

Method of Hardness Scale (MOHS)

Testing of tile for surface resistance to scratching by using different materials. A tile that would scratch by applying talc powder to the surface would receive a rating of 1, while a rating of 10 would be given if the surface could not be scratched by a diamond. A rating of 5 would be suitable for residential. A rating of 7 or higher would be suitable for commercial use.

Coefficient of Friction (COF)

This measurement is used to determine the aspects of slippage on a tiled surface. This includes wet and dry conditions, as well as the speed of the subject, the required force to move that subject and the angle of the tiled plane.

  • Slip Resistant - Coefficient of friction .60 or greater (wet) [Meets or exceeds ADA and OSHA requirements]
  • Conditionally Slip Resistant - Coefficient of friction is .50 to .59 (wet) [Meets or exceeds OSHA requirements]
  • Questionable - Coefficient of friction less than .50

Water Absorbtion Scale

This measurement represents the quantity of water that a single tile can absorb expressed as a percentage of the dry weight of the tile. High water aborption corresponds to a highly porous structure. Compact, or vitrified structures will feature low water absorption. 

  • Non-Vitreous - Tiles are tiles that absorb 7% or more moisture. They are suited for indoor use only.
  • Semi-Vitreous - Tiles are tiles that absorb from 3% to 7% moisture. They are applicable for indoor use only.
  • Virteous - Tiles are tiles that absorb less that 3% moisture. They are referred to as frost resistant tiles but cannot be used in exterior areas where freeze- thaw conditions could cause tile cracking.
  • Impervious - Tiles are tiles that have less than .5% moisture absorption. These tiles are frost proof and can be used in exterior areas or on the outside of building facades. You can use these where winter is for real.