The photographs below are from a set of Terrazzo steps outside a house in Glasgow which had completely lost their colour after being subject to years of weather staining and believe me we see all sorts of weather up here in Scotland. The owner of the house wanted them restoring back to their natural state but naturally concerned about safety didn’t want them shiny or slippy in anyway.
Cleaning Terrazzo Steps
I could see tackling the different surfaces of the stone stairs would be tricky so rather than opt for a cleaning product I decided to use a set of diamond encrusted burnishing pad fitted to a handheld flex machine.
I started with the very coarse 50 grit pad lubricating along the way with a little water and moved up through the medium and fine pad until the job was finished. Now normally when working on stone this is followed up with the application of a very fine pad to restore a polished appearance but clearly in this case that would not be necessary. In between the application of each pad the steps were rinsed with water to remove the slurry generated in the burnishing process.
One complete I left them to dry out for a few days; fortunately I had timed my visit within a warm weather window so I was confident they should be dry when I returned.
Sealing Terrazzo Steps
I returned a few days later and after checking the stone had indeed dried out I sealed the Terrazzo with three coats of Tile Doctor Colour Grow which is a breathable impregnating sealer suitable for external application. Being an impregnator it protects the stone from within by occupying the pores in the stone where dirt might otherwise become ingrained, it also enhances the natural colours in the stone and as you can see from the photograph below the steps now look much pinker.