WATER ABSORBTION ( EN ISO 10545-3 / ASTM C373 )

Other than hardness, a particular and important consideration for porcelain tile is moisture

absorption. The American National Standards Institute (ANSI) has developed a rating for

moisture absorption by tiles. This rating is actually a procedure to test a tiles permeability to

water. It consists of boiling the tile in water and measuring its gain in weight from the original

dry state.

Water absorption rates are a measurement of how much moisture a specific type of porcelain

tile is likely to absorb on an ongoing basis. Some types of tile may crack if the moisture

penetration is too high. Descriptions of the types of porcelain tile most suitable for your

project comprise of four ratings, and are classified as under:

(Low dense) Dry pressed Tile with water absorption of more than %10 percent I=L 2:BIII (Medium dense) Dry pressed Tile with water absorption ; %3 < A (absorbtion) < %6 l=J 2:BIIa (High Dense) Dry pressed Tile with water absorption ; %0.5 < A (absorbtion) < %3 l=H 2:BIb (Extremely dense) Dry pressed Tile with water absorption of % 0.5 percent or less I=G 2:Ba. This is where porcelain tile is categorized

Reflecting the density of the tile body, ceramic tile are also classified by their water

absorption rate apart from the resistance to wear and tear. The water absorption rate is

directly related with the suitability of the various types of tile for interior or exterior

applications. For exterior applications, the selected tiles must have a very low water

absorption rate, especially in climates subjected to rainfall, freezing and thawing cycles. A low

water absorption rate also enables a tile to absorb food or beverage stains on a lesser

percentage. This is usually a porcelain tile, which has a moisture absorption rating of less than

0.5 %