Method of making a composite surface elements of stone and lightweight sheet material

A method of manufacturing composite surface elements each comprising a lamina of natural facing stone bonded by adhesive to a backing sheet consisting of a core of light-weight sheet material which is resistant to compressive forces in a direction substantially normal to the plane of the sheet, comprising the steps of:

• i. cutting a block of natural facing stone into a number of slabs, two opposite faces of which are substantially parallel and each of which has a thickness greater than twice the thickness of the desired lamina;
• ii. drying the cut slabs;
• iii. applying and bonding to each of the two opposed faces of each stone slab a backing sheet comprising a core of light-weight sheet material which is resistant to compressive forces in a direction substantially normal to the plane of the sheet;
• iv. positioning each slab, with the backing sheets attached to the opposite faces thereof, between oppositely arranged vacuum-operated suction caps;
• v. applying suction to the cups to hold the slab rigidly in position therebetween;
• vi. sawing the slab in two along a cutting plane substantially parallel to and midway between said faces to leave a thin stone layer adhered to each said backing sheet, and during said sawing step maintaining said suction to prevent relative movement of the partly-cut stone layers;
• and
• vii. before or after the sawing step bonding a skin of sheet material of greater tensile strength than the backing sheet to the surface of the core opposite the stone lamina.