Clean, dry, test, then seal grout lines and stone tiles to stop stains and water damage, letting each coat cure fully.
SG-01Clear and ventilate the roomMove furniture and rugs out of the way and sweep the floor. Open windows and doors, especially if using a solvent-based sealer, as fumes can build up quickly in a small bathroom or kitchen. Lay a dust sheet over anything you can't move.
SG-02Deep-clean the tiles and groutUse a pH-neutral stone cleaner, not bleach or an acidic bathroom cleaner, which can etch natural stone. Scrub the grout lines with a soft brush to lift out old dirt and any failed sealer. Rinse well with clean water and mop, then leave the floor or wall completely alone.
1 litre · pH-neutral stone cleaner 1 each · Soft scrubbing brush SG-03Let the stone dry out completelyNatural stone is porous, and sealing over damp stone traps moisture underneath, which causes patchy staining later. Leave the tiles for at least 24 hours, longer in a bathroom or kitchen with poor ventilation. If unsure, tape a small square of clear plastic to a tile overnight; condensation underneath means it's still damp.
SG-04Test the sealer firstApply a small amount to a spare tile offcut or a hidden corner, such as under a cabinet. Wait the time stated on the tin, then check the colour and finish. Some sealers darken natural stone slightly, so it's worth knowing this before doing the whole floor.
1 each · Grout and stone sealer (test amount) SG-05Seal the grout linesRun a small applicator brush or sealer pen along every grout line, working in short sections. Wipe off any sealer that gets onto the stone surface within a couple of minutes, before it starts to dry.
1 250ml bottle · Grout sealer 1 each · Small applicator brush SG-06Seal the stone tilesApply an impregnating stone sealer with a foam applicator pad or lint-free cloth, working in small sections about 1m² at a time. Check the tin for coverage per litre, as this varies a lot between stone types like limestone, travertine and slate.
1 litre · Impregnating stone sealer 1 each · Foam applicator pad 1 pack · Lint-free cloths SG-07Wipe off excess and buffWithin the time stated on the tin, usually 5 to 15 minutes, buff off any excess sealer with a clean dry cloth. Left to dry on the surface, excess sealer forms a hazy film that's hard to remove. Apply a second coat if the manufacturer recommends it for porous stone.
1 pack · Clean dry cloths SG-08Leave to cure and tidy upKeep the floor or wall free of foot traffic and water for the time stated on the tin, often 24 hours for light use and up to 72 hours before it can get wet. Keep the room ventilated until any solvent smell has gone. Lay solvent-soaked rags flat outside to dry before binning them, as bunched oily rags can catch fire on their own.
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