Use and Care Guide
RECOMMENDED OFFSET FOR BRICK JOINT PATTERNS
A 50% offset is not recommended on large format square and rectangular tile due to
standard manufacturing tolerances.
A 33% max offset is preferable and proper grout joint width must be used to prevent the
appearance of lippage.
When tile cup or bow within tolerance they usually do so at the ends of the tile. As a result,
you should avoid a 50% offset as cupping may become more noticeable. By setting the
offset at a 1/3 ratio any cupping or bowing at the ends will blend into adjacent tiles.
Rectangular tile flatness: Rectangular tile in compliance with ANSI A137.1 (Ameri-
can National Standard Specifications for Ceramic Tile) are suciently flat for success-
ful lippage-free installations. ANSI A137.1 defines acceptable edge warpage as a
percentage of the tile’s edge length, and also sets a maximum allowable warpage
amount in millimeters regardless of tile size.
For example, a 6” rectified porcelain tile’s maximum allowable warpage, based on
the allowable edge warpage percentage criteria, is 0.6 mm, while a 24” calibrated
tile’s maximum allowable warpage “caps out” at 1.3 mm, or nearly 1/16”. Therefore,
patterns and grout joint accommodations that work well with smaller tiles would
not work with larger tiles exhibiting the maximum allowable warpage. Such tiles
that are just barely within ANSI tolerances are not generally recommended for offset
patterns and can be highly problematic when installed with a 50% offset and a
narrow grout joint.
INDUSTRY TOLERANCES
COMMON MISCONCEPTIONS
ABOUT LIPPAGE
Many customers and installers may not be aware of the manufacturing and installation
standards set forth by ANSI, ASTM and TCNA. Most people think that everything must line
up 100%, be square, level and contain no variation at all. If there are any subtle variations
in the size, shape or thickness of the tile, the product is often considered defective. This
assumption is in fact false.
The reality is that some imperfections are acceptable by industry standard as it is the
nature of all fired products.
ABOUT GROUT JOINTS
Rectified porcelain tile is a good example of a common industry myth. Because the edges
are cut / grinded to a 90-degree angle around the perimeter of the tile, the most
common thing you hear is to go closer with the grout joint. Although this is sometimes
true, rectified products also have a warping and wedging tolerance to accommodate
blade cuts and settings for grinding the edges. Butt joints or close joints are not always
suitable. Technically, according to the wedging tolerances in ANSI A137.1, tile can warp
“out of square” up to 0.8mm. With a very close grout joint over a span of an application,
the tile can misalign.
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