Porcelain tile is ceramic tile with a water absorption of .5% or less. Porcelain tile is independently tested and confirmed to comply with the water absorption requirement, and are certified by the Porcelain Tile Certification Agency. Porcelain tile in compliance with ANSI A137.1 is considered impervious, and requires specific bonding materials because of its low water absorption.
Porcelain tile provides greater abrasion and thermal shock resistance than ceramic, and is therefore suitable for exterior applications.