Can terrazzo be repaired?

Yes, and it is the reason this material is worth specifying. A chip is filled with a mix matched to the existing matrix and aggregate, ground flush and sealed. The US General Services Administration publishes the procedure. What it does not do is fix movement — a crack caused by a slab still moving will come back.

The six processes drawn to one scale. Layer thicknesses are published ranges.

Reference photograph of a terrazzo surface, s64. Not a photograph of our goods. — A stair nosing. The profile is where a floor takes the most impact, and where a patch has to match.

Reference photograph of a terrazzo surface, s61. Not a photograph of our goods. — A curved edge. Repairing a curve is the test of whether a floor can be matched or only replaced.

Reference photograph of a terrazzo surface, s86. Not a photograph of our goods. — A bar top cast in offcuts. Cut-to-fit pieces are what precast is for, and what a patch has to match.

Reference photograph of a terrazzo surface, s06. Not a photograph of our goods. — Panels laid flat. A panel can be replaced; a pour cannot be, which is why the process decides the repair.

Reference photographs. They show the material and the finish; they are not photographs of goods we made, and the colour on screen is not a colour-match.

The figures, and where each one comes from

Item	What the trade publishes	Source
Chip or gouge, cement matrix	cement grout plus matched terrazzo topping; 40 then 80 grit sanding; penetrating sealer pH 7 to 10	GSA Preservation Note
Chip or gouge, resin matrix	two-component epoxy with matched aggregate, forced into the void; grind flush	GSA Preservation Note
Crack wider than 1/4 inch	use aggregate, not filler alone	GSA Preservation Note
Grouting cure	minimum 72 hours, ambient 70 to 80 F	GSA Preservation Note
Epoxy set before walking	minimum 24 hours	SFGate repair guide
Divider strips	retain where possible; replace in solid metal matching size, colour, sheen	GSA Preservation Note
Joint at a repair edge	saw-tooth, with loose matching chips while the resin is still wet	GSA Preservation Note
Grinding across a patch	24 grit or finer in water, then 80 or finer; avoid divider strips	GSA Preservation Note
Epoxy matrix and UV	epoxy alone yellows; an aliphatic polyurethane sealer is required where UV reaches the floor	Manufacturer CSI spec
Cement matrix and acid	alkaline and acid-reactive; acid attack is a substrate question, not a cleaning one	Stone Polishing Solutions

Why the processes are not interchangeable

Terrazzo is a through-body material, so a damaged surface is ground back rather than replaced. That is true of both a cement and a resin matrix, and it is the one capability no tile has: a chipped porcelain tile is replaced, a chipped terrazzo floor is patched.

What these figures are, and what they are not

We have not repaired a floor and measured the result. The procedure below is the GSA one, not ours. What we do is supply the matrix and the aggregate to match an existing floor, and we will tell you when the honest answer is that the floor needs replacing.

Measured data sheets and test reports

If you are specifying this

We have not published products against this question yet. Send us the process, thickness and quantity and we will quote it against what we can actually form, rather than against a catalogue.

Send a specification Ask for a sample