What is Nominal Tile Sizing?
If you are planning to install tiles in your home or office, you may have come across the term “nominal tile sizing”. What does it mean and why is it important? In this blog post, we will explain what nominal tile sizing is, how it differs from actual tile sizes, and what factors affect the size variation of tiles.
Nominal tile sizing refers to the expected production size of the tile plus the joint size. For example, a tile with a nominal size of 600 x 600 mm will typically have a production size of 597 x 597 mm (+3 mm joint width). The joint size is the space between tiles that is filled with grout or adhesive. Nominal tile sizing is used by manufacturers and retailers to indicate the approximate size of tiles, and it is usually stated on the box or website.
Actual tile sizes are the exact dimensions of each individual tile, measured from edge to edge. Actual tile sizes may vary slightly from nominal tile sizes due to manufacturing and production processes. For instance, tiles may shrink or expand during firing, cutting, or polishing. The variation may be up to 2 mm for non-rectified tiles, or up to 0.5 mm for rectified tiles.
Rectified tiles are tiles that have edges that have been mechanically cut or ground down for uniformity. This ensures that each tile is exactly the same size as the next one within a product line. Rectified tiles allow for minimal grout joints, giving a sharp and seamless finish to the project. Non-rectified tiles are tiles that have natural or moulded edges, which may have slight angles or curves. Non-rectified tiles require wider grout joints to accommodate the size differences and to avoid visible gaps or unevenness.
The size variation of tiles is subject to standard industry tolerances, which are acceptable ranges of deviation from nominal sizes. The tolerances depend on the type and quality of tiles, as well as the standards of different regions or countries. For example, the European standard EN 14411 specifies a maximum tolerance of +/- 0.6% for rectified porcelain tiles, and +/- 2% for non-rectified porcelain tiles.
Nominal tile sizing is a useful way to compare and choose tiles for your project. However it is not a guarantee of exact dimensions. Therefore, it is important to measure your actual tiles before installation and to follow the manufacturer’s recommendations for joint width and layout. By doing so, you can ensure a professional and beautiful result that meets your expectations.