What is Calibrated Sandstone and why use it

What is Calibrated Sandstone Paving 

Calibrated Slate and sandstone paving is a way of finishing off Flagstones and Slabs of various thickness into a standard thickness (rather like a tile) in our case 20mm or 22mm. This is mainly produced with stones from India and China .
         Theses can be used and laid on a level screed bed rather than the harder to use un-calibrated stone paving. The calibration takes place on the under side of the stone and generally you will see lines running on the underside where the machinery has been used to level it off.
          Whilst Calibrated natural stone is more expensive than standard  non calibrated most landscapers quote less for laying so you should make them aware that you are going to purchase Calibrated and if you are using it yourself you will find it much easier to use.

Reasons to Use Calibrated Stone Paving
Easier to lay . No variance in thickness. Lighter to pick up and carry, Cheaper Costs for having laid. More cost effective when it comes to delivery costs  (up to 22sq mts per tonne)