As this is a difficult substrate to gain a key to, a good clean and degrease would be recommended using hot soapy water, rinsing with warm water then wiping over with Methylated Spirit.

Once this is done, the marble is clean, dry and sound we would recommend Zinsser Bulls Eye 1-2-3 followed by 2 coats of Zinsser AllCoat Exterior (Water Based).

This is available in many RAL, NCS or BS colours in a matt, satin or gloss finish.