Terrazzo, ground flat and polished back.
Terrazzo is chips of marble or granite set in a binder. Most of it is stone, so it grinds and polishes like stone, and a dull terrazzo floor usually has years of coating and traffic sitting on a surface that is still sound underneath.
Terrazzo is an aggregate surface: chips of marble, granite or glass set into a binder and ground flat once it has cured. It is either poured in place over a slab or supplied as precast tiles and treads. The binder is the part that decides the method. Cement-based terrazzo, which is most of what sits in Sydney apartment foyers and older houses, is porous where the cement shows between the chips. Epoxy terrazzo, which is newer and more common in commercial fitouts, is not porous at all and grinds harder.
What goes wrong is usually not the terrazzo. Older floors were finished with wax or an acrylic coating that was stripped and reapplied for years, and each coat yellowed a little more. Traffic lanes wear through the coating first, so the floor reads as two colours. Where the coating has gone entirely, the cement between the chips takes stains, because that is the soft, open part of the surface. Panels can sit at slightly different heights, and chips occasionally lift where the binder has failed beneath them.
The work is grinding, not cleaning. Whatever is on top comes off first, mechanically, because a floor that has been coated cannot be assessed until the coating is gone. If the panels are uneven the first pass grinds them level, which is the step that makes the difference between a floor that looks clean and a floor that looks flat. After that it is the same progression as stone: hone through the grits, polish to the finish you want, and seal with a penetrating sealer rather than another coating, so the next twenty years do not repeat the last twenty.
Where the limit sits: a chip that has lifted can be refilled, but the fill is a patch and it is visible up close on a floor with a distinctive aggregate. Terrazzo with asbestos in the original binder, which does turn up in floors of a certain age, is not ours to grind and needs testing before anyone touches it.
Questions about terrazzo.
Can etched marble be restored, or does it need replacing?
Etched marble can be restored in place, and replacement is almost never the right answer. Etching is a thin layer of the polished surface dissolved by acid. It is not a stain and it does not go deep. The mark is honed off with diamond abrasives and the area is re-polished to match the rest of the top. On a benchtop that is usually a couple of hours of work, done on the bench with the kitchen protected. Deep etching that has left a visible dip takes more honing and blends less perfectly, and that is exactly the sort of case we cut a test patch for before committing. Replacing a benchtop means a new slab, templating, fabrication, removal, plumbing and a splashback, and weeks without a kitchen. Restoring it is a fraction of that.
How long does a marble floor restoration take?
A large entry or open-plan floor is usually two to three days. A single room is a day. The time goes into grinding, honing, polishing and sealing, each pass across the whole floor, with drying time between the last polish and the sealer. Rooms can stay in use around the work; we move through the house in sections so you are never locked out of everything at once. The floor is walkable the same day it is polished and fully cured a day or two after sealing. We give you a schedule before starting so you know which rooms are out of action and when.
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