How to distinguish clay tiles and porcelain tiles?

Traditional Chinese clay roof tiles was the oldest tiles for covering ,which appeared in Western

Zhou dynasty. It has 3000 years history.

The common between clay tiles and porcelain tiles are unglazed surface, grey color and same type.

The differences

1. Material

Clay tiles are made of natural clay .Porcelain tiles are made of iron ore.

2.Sintering technology

 After molding clay tiles are fired in earth kiln by coal. The tiles are fumigated and water immersion.

Gradually the surface appear grey color. You also can find there is a layer coal ash on the surface.

The color looks gentle for ancient buildings.

Porcelain roof tiles are sintered in modern kiln and fired by natural gas. So the surface is more smooth

and clean. The color is a little deeper.

3. Water absorption

  For the material and technology the traditional clay tiles are easy to keep water. The rate is

about 8%. But the porcelain tiles are only 1-2%. So the porcelain tiles are better to use for buildings

in cold climate and can keep in good condition for long years.