Terrazzo Maintenance and Resealing: A 10-Year Program

A correctly installed terrazzo floor will outlast its building. What determines whether it looks like a 50-year-old institutional floor or a 50-year-old museum floor is the maintenance program. The program isn't complicated, but it has to be followed consistently, and the wrong products can do real damage in a few months.

The basics

Daily

• Dust mop or microfiber sweep to remove grit. Grit is what wears the polish off — abrasion happens between the floor and tracked-in sand.
• Walk-off mats at every entry, minimum 12' length. Captures 80%+ of incoming grit.
• Spot-clean spills immediately — most are harmless if cleaned within an hour. Acidic spills (citrus, vomit, vinegar) need immediate flushing.

Weekly to monthly

• Auto-scrub with neutral-pH detergent at manufacturer-recommended dilution.
• Inspect entry mats; replace when matting flattens.
• Inspect divider strips for any unevenness; report immediately — divider damage is repairable if caught early.

Annually

• Machine burnish with high-speed propane or electric burnisher. Restores gloss without removing material.
• Inspect sealer; spot-reapply at high-traffic zones if dulling is visible.
• Document floor condition for the facility maintenance record.

Products that protect

Products that damage

Several common cleaning products will damage terrazzo. Train facility staff on what NOT to use:

• Acidic cleaners (citrus, vinegar-based, descalers, toilet-bowl cleaners): etch the marble matrix and aggregate. Dulls the surface permanently.
• Strong alkaline strippers (ammonia, sodium hydroxide): break down the matrix bond and can re-emulsify the sealer.
• Oil-based dust mop treatments: leave a residue that traps soil and dulls the floor.
• Floor waxes formulated for vinyl or linoleum: yellow under UV and lock in dirt.
• Steam cleaners above 200°F: thermal cycling can stress the matrix and the bond to the substrate.

The 5–10 year re-polish

Even with a perfect maintenance program, terrazzo gradually loses gloss as the sealer wears and microscopic abrasion accumulates. Every 5–10 years (closer to 5 for high-traffic civic spaces, closer to 10 for low-traffic offices) the floor benefits from a re-polish.

Re-polishing is different from re-grinding. Re-polishing removes essentially no material; it works through fine grits (400 through 1500 or higher) with a planetary diamond polisher to restore the optical clarity of the surface. The aggregate field, color, and divider strips are unaffected. Re-grinding is a deeper operation — removing 1/64"+ to address damage — and is rarely needed in commercial service.

After re-polish, the sealer is reapplied. The floor returns to original-install appearance.

Repairing damage

Localized damage — chips from heavy-impact, gouges from dropped equipment, hairline cracks from substrate movement — can be repaired without re-pouring the floor. The technique:

1. Rout out the damaged area to a clean, sound substrate.
2. Match the aggregate blend and matrix color to the existing field (this is why your installer should retain a sample of the original blend).
3. Patch-fill, level, and grind flush.
4. Polish through grits to match the surrounding finish.
5. Re-seal locally.

A well-executed patch is visible to a trained eye on day one and invisible to anyone else within 90 days.

Coved-base and joint maintenance

Integral coved base in healthcare and lab environments needs periodic inspection at the cove transition — that's where wheeled-cart impact concentrates. Re-caulk expansion joints every 5–10 years; the terrazzo doesn't move, but the sealant ages. Use color-matched two-part urethane or silicone, not acrylic.

Frequently asked