Classification of ceramic tiles with respect to water absorption and shaping

Ceramic tiles are classified in to 3 major groups and sub groups of them as per the water absorption and the manufacturing method.

Shaping	Group I E < 3 %	Group IIa 3 % < E , 6 %	Group IIb 6 % < E , 10 %	Group III E . 10 %
A   Extruded	Group AI (see annex A)	Group AIIa–11) (see annex B)	Group AIIb–11) (see annex D)	Group AIII (see annex F)
		Group AIIa–21) (see annex C)	Group AIIb–21) (see annex E)
B Dry pressed	Group BIa E < 0,5 % (see annex G)	Group BIIa (see annex J)	Group BIIb (see annex K)	Group BIII 2) (see annex L)
	Group BIb 0,5 % , E < 3 % (see annex H)
C Tiles made by other processes	Group CI 3)	Group CIIa 3)	Group CIIb 3)	Group CIII 3)
1)  Groups AIIa and AIIb are divided into two parts (Parts 1 and 2) with different product specifications. 2)  Group BIII covers glazed tiles only. There is a low quantity of dry-pressed unglazed tiles produced with water absorption greater than 10 % that is not covered by this product group. 3)  These tiles are not covered in this International Standard.