Even a terracotta floor that is over a century old can be revived to a high gloss shine when the surface is restored properly before polishing. Use the procedure outlined below to bring your old terracotta floor back to a gleaming finish.
Step 1: Determine the State of Your Old Terracotta Floor
If your old floor is stained, discolored and has white flaky mineral patches called efflorescence, you will need to completely strip the floor's existing finish before shining it. If the terracotta floor is merely dirty and has some wax buildup, but still is sealed against water penetration, you can clean off the old finish more easily. In an inconspicuous corner, splash some water on the terracotta floor tiles. If the water beads up and stays in one spot, your floor's sealant is still intact. If the water spreads out and is absorbed, you will need to strip the floor surface down to bare tiles.
Step 2: Clean and Strip the Old Finish
Use a heavy-duty stripper for sealant and waxes to remove old finishes down to bare tiles. Choose a multi-surface stripper to remove old wax and synthetic-based floor polish if the sealant is still effective. Mix the stripper in the concentration indicated on the directions, in a large bucket. Apply the solution with the fiber mop from a bucket, leaving it on the tiles for up to 30 minutes. Scrub at spots where sealant peels off to loosen it. Rinse off the solution, using first warm, then cold water, and go over the floor with a shop vacuum to ensure all the stripper is removed.
Step 3: Spot-Clean Tile and Grout
With a tile and grout cleaner made for clay tiles, clean up any stained or discolored spots, scrubbing with a grout brush. Rinse away the tile and grout cleaner, and vacuum damp spots with the shop vacuum.
Step 4: Apply Terracotta Tile Sealant
If the floor has been stripped to bare tiles, sand it lightly and vacuum up the dust before applying tile sealant. If you are applying the sealant to create a high-gloss finish, spread the sealant onto the dry smooth floor with a fiber mop. Make the first coat a generous, thick layer and allow that coat to dry for 2 hours. Using the power buffer, go over the entire terracotta floor evenly with the soft buffing pads to start bringing up the shine. Wait 1 hour after buffing and pour on the second coat of high-gloss sealant. Allow 2 hours of drying time, and buff once again.
Step 5: Maintain the High Gloss Shine
Buff the floor surface twice a week in halls and doorways. Use the power buffer on the entire floor at least once a week to maintain its new warm glow. Avoid using paste wax, urethane sealers or other floor polish formulas on your glossy terracotta floor. They will cause yellowing and diminish the effectiveness of the tile sealant.