How to Check Ceramic Tiles Quality?

Once you have selected the color and size of the ceramic that you will use for the floor or wall of your house, you should check the quality of the ceramic tile.The first step you should do to check the quality of the ceramic tile is to ask the suppliers. Is the quality of the ceramic tile you selected that is the best?

It is also a common practice that tile size, color shade and other information are printed on each carton.

Checking the quality of the ceramic tile needs to be done because impact of manufacturing processes on tile quality.

 

Here are some guidelines you can do to check the quality of ceramic tiles:
a. Size variation
b. Warpage
c. Water absorption, surface cracks and damage
d. Shade variations

 

Size variation

Size variation will lead to inconsistent joints

Size variation will lead to inconsistent joints

Other than poor workmanship, inconsistency in tile joints is due to dimensional variations among the tiles. This variation occurs mainly during the kiln firing as the bisques tend to shrink during this process and the shrinkage may not be constant in all tiles. This result in different tile sizes and the variation can be up to 1% of the tile size depending on the manufacturing process and the kiln atmosphere.

The inconsistent joints can be substantially reduced by using rectified tiles which require the additional process of cutting and grinding after kiln firing. The rectified tiles with controlled tile dimensions and straighter edges make the joints consistent and aesthetically pleasant.

 

Warpage
Warpage is curvature in the face of a tile which can be concave or convex in shape. This is due to changes that occur during the firing and cooling process of production. Edge warpage is measured at the centre of a tile’s edge and diagonal warpage is measured at the center of the tile. Both are expressed as a percentage of the tile’s linear dimensions. Most tiles (both homogeneous and ceramic tiles) will exhibit some warpage after firing.

Depth gauge used to measure lippage or unevenness between tiles

Depth gauge used to measure lippage or unevenness between tiles

Tile warpage is often the cause (apart from poor workmanship) of lippage or unevenness between tiles. Lippage is a condition where one edge of a tile is higher than adjacent tile, giving the finished surface a ragged and uneven appearance. Lippage in floor tiling often causes discomfort to end users walking with bare feet and may result in injury especially on sharp edged tiles. It also affects the visual appearance of the floor and in wet areas, it can impede water flow and build up stagnant water.

 

Water absorption, surface cracks and damage
The raw material used and the manufacturing process affect the density of the tile. This in turn controls the water absorption rate of the tile. There is a direct relationship between the water absorption rate and the suitability of the tile for interior or exterior use.

Crazing is a defect or phenomenon in a glazed tile where thin cracks appear on the surface. This is usually caused by tensile stress between the bisque and glaze. When the bisque and glaze expand and contract at different rates, fine cracks may appear on the glazed surface. The other reason could be thermal shock where in the kiln, the tiles are either brought up to high temperature too soon or cooled too quickly.

Degree of Hardness of a tile is achieved by the choice of raw materials used and the manner in which the tile is manufactured. Ceramic tiles are made from clay and not all clays have the same properties and mineral content. During the manufacturing process the soft clay tiles are subjected to high temperatures in a kiln. The final hardness of the tile is directly related to the mineral content, the temperature reached in the kiln and the duration of time the tiles are fired. MOH (Measurement of Hardness) test is used to rate the tiling hardness from 1 (softest) to 10 (hardest). Ceramic tiles with a value of 5 or more are suitable for most residential floor tile applications. Tiles with a value of 7 or higher are normally acceptable for most commercial applications or heavy traffic areas.

 

Shade variations
The variation in color, texture and tone between individual tiles is termed as shade variation. Shade variation is an inherent characteristic of majority of fired ceramic products. The color is bound to vary to some degree in each production run. So it is important to purchase sufficient quantity of tiles from the same batch of production to complete the job. If not, obtaining additional tiles from a different batch production even from the same factory may lead to shade variation.

1 Comment

  • Srinivasan October 9, 2018 at 5:57 am

    What is meant by phase and face in tiles

    Reply

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