Why is slate calibrated ?

You will note when browsing our website that all of our slates are calibrated to the rear of the tile . This means that there is a natural riven face with a flat back.

When the slate is quarried in China it comes out in very large blocks of 4000kg. This is then split or sawn down to manageable sizes to be split by hand. The slate will be graded down to pieces between 10 and 15mm. Then using a diamond tipped horizontal calibrating machine the thickness will be set to 10, 12 or 15mm.

This is quite a rigorous process and some slates or mudstones are too soft to take this kind of treatment and will be supplied un-calibrated with a thickness of 10-16mm

The advantages when using calibrated slate are as follows :

Ease of installation as you do not need to select the thickest tiles first.

Reduced cost on installation as you will need to use less adhesive.

Reduced change of tiles loosing adhesion with the adhesive.

Reduced and known overall weigh of the product .