American National Standard Specification A137.3 describes the minimum physical properties and grading procedures for gauged porcelain tiles and gauged porcelain tile panels/slabs. It provides quality criteria for buyers, specifiers, installers, manufacturers, and the public in general. Gauged means manufactured to a thickness that is specific and largely associated with installation and use. Tile panels/slabs are those that are one square meter in facial area or larger. Some of the key issues addressed by this standard are:

-- Floor, wall, and countertop strength criteria for Table 4 gauged products that have a declared nominal thickness within the range of 5.0 to 6.5mm
-- Wall and countertop strength criteria for Table 5 gauged products that have a declared nominal thickness within the range of 3.5 to 4.9mm
-- Thickness accuracy and precision criteria
-- Provisions for sampling and visual inspection, considering tile panels/slabs can be very large
-- Provisions for gauged products with back layer reinforcing

American National Standard A108.19 provides procedures and requirements for interior installation of gauged porcelain tiles and gauged porcelain tile panels/slabs. These products require unique installation and workmanship considerations, and some of the key issues addressed by this standard addresses include:

-- Floor and wall installation procedures for ANSI A137.3 Table 4 gauged products
-- Wall installation procedures for ANSI A137.3 Table 5 gauged products
-- Substrate requirements
-- Lippage criteria and use of lippage control systems
-- Unique coverage criteria and evaluation procedures
-- Special floor setting provisions that involve embedding by walking

American National Standard A108.20 provides procedures and requirements for exterior installation of gauged porcelain tiles and gauged porcelain tile panels/slabs.  These products require unique installation and workmanship considerations, and some of the key issues addressed by this standard addresses include:

-- Exterior vertical and overhead installation procedures for ANSI A137.3 gauged products
-- Substrate requirements
-- Lippage criteria and use of lippage control systems
-- Unique coverage criteria and evaluation procedures
-- Specific embedding instructions