Clean the non-sealed, unpainted, untreated surface of brick, concrete block or other wall. On all other surfaces apply metal lath. On metal surface attach the metal lath using self-tapping screw every 40 cm. On wooden surfaces attach the metal lath using nails or stitches every 15 cm and driving decorative nails wherever possible. The metal lath should always be attached from the right side and upwards using small nails with semicircular heads directed upwards. On external surfaces an insulating material should be applied before attaching metal lath.

When the bonding becomes firm, the surplus mortar should be removed by chipping with a wooden or metal tool. Simultaneously the mortar should be pressed in between the slabs to seal the edges carefully.

Clean the stones from any leftovers of the mortar with a wire brush. If you wish you may use water-proof sealing such as Thoroclear or Chemstop, which will facilitate cleaning the surface.

Apply thin layer of the mortar, 1.2-1.8 cm thick. Mix the mortar with the appropriate amount of water to obtain proper consistence.

Arrange the slabs at random (i.e. not in any special arrangement). Install the corner slabs first. The other slabs should be laid from downward to upward or from upward to downward. The joints between slabs should be as narrow and homogenous as possible. 
Push the slab firmly in its place with a delicate up-and-down movement to strengthen the bonding. The mortar should flow out from behind the slab and surround it.

Use the special broom for removing the mortar from the joints until they are smooth and the excess mortar is cleared away. Brush any mortar remaining on the slabs. On no account may the mortar be left for the night without cleaning the joints.

To additionally protect the stone you may cover it with RG-DC preparation, which may be purchased from the producer of the stone. RG-DC will additionally harden the stone surface, link the cement dust, increase the abrasion resistance and protect from penetration of liquids, greases, oils etc.