Flatness
In most instances all kinds of ceramic tiles may exhibit a degree of curvature or warpage after the tile body is formed and fired. In normal circumstances these variations are minimal. ISO 10545-2 ‘Determination of Dimensions and Surface Quality’ sets out the permitted tolerances. There are three types of variations possible:
Manufacturing tolerances are expressed as a percentage of the tile’s linear dimension. For dust pressed ceramic tiles with a water absorption of less than 10% the standard permits a variance of curvature and warpage of + or –0.5% of the dimensions, providing the variance does not exceed + or –2 mm.
For dust pressed ceramic tiles with a water absorption of greater than 10% (most typically a wall tile) the standard permits a variance for curvature of +0.5%, providing the variance does not exceed 2 mm or, -0.3%, providing the variance does not exceed 1.5 mm. For warpage the standard permits a variance of + or –0.5% of the dimensions, providing the variance does not exceed + or – 2 mm.
The allowable curvature for first quality ceramic tiles whether plain, polished or honed, according to AS4459 and the ISO standard remains at 0.5%. This allows a 600x300mm tile to curve up to 3mm in its length and still be considered first quality. For different edge finishes please see below:
Natural: -0.12" to +0.12”
Calibrated: -0.08” to +0.08”
Rectified: -0.05” to + 0.05”
Keep in mind that with tiles becoming larger and longer, they proportionately can include more actual or inherent warpage.
Modern production techniques and quality control processes ensure that a vast majority of the tiles marketed in Australia comply with the parameters set in the Standards.
Curvature can be a problem when rectangular products are laid in a brick fashion design, where the centre of one tile abuts the end of two adjacent tiles, this might highlight any curvature which exists. Tiles should be loose-laid on a flat surface prior to the commencement of the fixing process. If curvature is evident, the laying pattern can be adjusted to overcome the problem.
The tile fixer should check the flatness and soundness of the prepared surfaces and the flatness of the tiles. Any major deviations should be reported to the client before fixing commences.
Credit: Australian Tile Council
- Centre Curvature is the deviation of the centre of the tile from the plane defined by the corners of a tile.
- Side Curvature is the deviation of the centre of the tile from the plane, which is observed at the side and the corners.
- Warpage is the deviation which occurs when one or more corners curls upwards or downwards.
Manufacturing tolerances are expressed as a percentage of the tile’s linear dimension. For dust pressed ceramic tiles with a water absorption of less than 10% the standard permits a variance of curvature and warpage of + or –0.5% of the dimensions, providing the variance does not exceed + or –2 mm.
For dust pressed ceramic tiles with a water absorption of greater than 10% (most typically a wall tile) the standard permits a variance for curvature of +0.5%, providing the variance does not exceed 2 mm or, -0.3%, providing the variance does not exceed 1.5 mm. For warpage the standard permits a variance of + or –0.5% of the dimensions, providing the variance does not exceed + or – 2 mm.
The allowable curvature for first quality ceramic tiles whether plain, polished or honed, according to AS4459 and the ISO standard remains at 0.5%. This allows a 600x300mm tile to curve up to 3mm in its length and still be considered first quality. For different edge finishes please see below:
Natural: -0.12" to +0.12”
Calibrated: -0.08” to +0.08”
Rectified: -0.05” to + 0.05”
Keep in mind that with tiles becoming larger and longer, they proportionately can include more actual or inherent warpage.
Modern production techniques and quality control processes ensure that a vast majority of the tiles marketed in Australia comply with the parameters set in the Standards.
Curvature can be a problem when rectangular products are laid in a brick fashion design, where the centre of one tile abuts the end of two adjacent tiles, this might highlight any curvature which exists. Tiles should be loose-laid on a flat surface prior to the commencement of the fixing process. If curvature is evident, the laying pattern can be adjusted to overcome the problem.
The tile fixer should check the flatness and soundness of the prepared surfaces and the flatness of the tiles. Any major deviations should be reported to the client before fixing commences.
Credit: Australian Tile Council
