Floor sealing and protection: what a polish is, which floors take it, how to apply it, maintain it and redo it, with the method sheet to download

A new resilient floor, whether PVC, linoleum or thermoplastic, shines, washes easily and resists staining. Six months later, with no protection on it, the same floor is dull, scored by trolley wheels, stained along the traffic lanes, and every wash wears it down a little further. Sealing, or more accurately the application of a protective polish, is the technique that prevents this: one or more coats of a polymer film that take the punishment instead of the floor covering, and that can be buffed, repaired and redone. Done badly, it produces the opposite: a yellowed, powdery or peeling film that has to be stripped. This article explains what a polish is and why the trade still calls the job metallisation, which floors take it and which do not, the full method from stripping to the final coat, the maintenance that makes it last, spray buffing and burnishing, restoration, frequencies, common mistakes and safety. The method sheet is available as a PDF. Maintenance between two restorations, burnishing and spray buffing, has its own technical sheet.

What a protective polish is, and why the job is called metallisation

A protective polish is a water-based dispersion of polymers, usually acrylic, with waxes, plasticisers and coalescing agents. Spread in a thin coat over a clean, dry floor, the water evaporates, the polymer particles fuse and a continuous, transparent, glossy film a few microns thick is left behind. That film is sacrificial: it takes the scratches, the trolley marks, the stains and the wear of repeated washing instead of the floor covering. It can be buffed, repaired locally and redone.

The French word metallisation comes from so-called metallised emulsions, whose film is cross-linked with metal salts, most often zinc, which makes it harder and more resistant to detergents. Those emulsions dominated the market for decades, and the word stuck as the name of the operation itself. Today's polishes are mostly metal-free, for environmental and regulatory reasons, with comparable performance; the trade talks interchangeably about sealing, protection, polish or "laying a sealer and a polish". What the word refers to has not changed: strip first, then protect.

Protection does three things. It shields the floor covering from wear and staining, which adds several years to the life of a floor in a traffic lane. It sets the appearance, gloss or satin depending on the polish, and makes it uniform. And it makes routine cleaning easier: a protected floor washes with less product, dries quickly and can be brought back by burnishing between two restorations.

The floors that take a polish, and the floors that do not

Resilient and thermoplastic floors take a polish: PVC in sheet, tile or plank form, linoleum, rubber, vinyl floors, some poured floors, and the thermoplastic floors found in schools, hospitals, care homes, offices and shops. Linoleum, which is linseed oil based, needs a mild stripper rather than a strong alkaline one, and a compatible polish; PVC takes conventional alkaline strippers.

Two checks before sealing. Compatibility: read the floor manufacturer's instructions and run a trial in a corner. And the condition of the floor, because a polish hides neither deep scratches, nor lifted tiles, nor open joints; it locks them in.

The full method: strip, rinse, protect

• 1. Survey. Type of covering, condition of the existing film (worn, yellowed, peeling), scratches, ingrained stains, joints, tiles. Trial area in a corner. Choice of stripper and polish, with the technical sheet and the safety data sheet to hand.
• 2. Prepare. Area cleared of furniture, signed off and ventilated; skirtings and thresholds protected; damp sweeping; PPE: nitrile gloves, goggles, non-slip footwear.
• 3. Strip. Alkaline stripper diluted as stated on the sheet (mild on linoleum), applied generously with a flat mop over areas of 10 to 20 m², 5 to 10 minutes of dwell time without letting it dry, then a single-disc machine at low speed with a black or brown pad, and the soiled solution picked up with a wet vacuum. Corners and skirtings by hand pad.
• 4. Rinse and neutralise. At least two clean-water rinses, each picked up; a neutralising rinse if the polish manufacturer calls for one. Any stripper residue stops the polish adhering and makes it peel.
• 5. Dry. The floor must be completely dry, with no marks and no bloom, checked against the light. Drying is the point of no return: a polish laid on a damp floor goes white.
• 6. Apply the polish. First coat, over a sealer on a porous floor if needed, laid with an applicator (polish mop or applicator squeegee) in thin, even coats, crossing the passes, working from the far end towards the exit, never going back over an area that is already drying. Allow 30 to 45 minutes between coats depending on temperature and humidity. Two coats minimum, three to four on traffic lanes; lay the last one in the direction of the light.
• 7. Let it cure, then check. Back in service after at least 12 hours, furniture back after 24 hours, no washing for 48 to 72 hours. Check for even gloss, with no overlap marks, no bloom, no runs and no powdery patches.

The maintenance that makes it last: washing, spray buffing, burnishing

A well-maintained seal lasts one to two years; a badly maintained one, six months. Daily maintenance comes down to two operations: damp sweeping, which lifts the abrasive particles before they scratch the film, and flat mopping or scrubbing with a correctly dosed neutral detergent, never an alkaline one, which would take the protection off coat by coat. Effective entrance matting, dry and at least three paces long, holds back most of the grit and sand that wear films down.

Periodic maintenance is done by spray buffing and burnishing. Spray buffing means spraying a diluted restorer onto the traffic lanes, then running a high-speed single-disc machine with a red or beige pad: the micro-scratches close up, the film densifies again and the gloss comes back. Dry burnishing, with a high-speed single-disc machine or a burnisher, restores the shine between two spray sessions. Frequency: monthly on traffic lanes, quarterly elsewhere. A refresher coat of polish, on a clean dry floor, with no stripping, applied to worn traffic lanes, adds a year to the protection. It cannot be repeated indefinitely: beyond six to eight accumulated coats the film yellows and holds soil, and stripping becomes necessary.

Restoration and frequencies

Full restoration, meaning stripping and resealing, is decided on visible signs: the film is worn down to the covering along the traffic lanes, it has yellowed, it shows black marks that burnishing no longer lifts, it is peeling in places, or the accumulated coats have made it opaque. Frequency depends on traffic: every 12 months in the corridors of a hospital, a school or a shop; every 18 to 24 months in offices and low-traffic areas; more often in trolley zones. Plan it around closures, because the operation takes the area out of use for 24 to 48 hours.

The cost of a restoration should be weighed against the cost of the covering: a maintained seal adds several years to a PVC floor and avoids a replacement that costs ten to twenty times more. It is one of the few cleaning budgets that pays for itself in capital expenditure avoided.

Common mistakes and safety

• Sealing without stripping: fresh polish over a worn film locks in the soil and yellows; every restoration starts with stripping.
• Under-rinsing: alkaline residue stops the film adhering and makes it peel.
• Laying on a damp floor, or in thick coats: whitening, runs, incomplete drying.
• Washing with an alkaline product: the daily degreaser strips the protection; routine washing is done with a neutral detergent.
• Endless recoating: beyond six to eight coats, strip.
• Stripping linoleum with a strong alkaline: it damages the material; use a mild stripper and a compatible polish.
• Safety: strippers are corrosive (nitrile gloves, goggles, ventilation, safety data sheet, never mixed with a chlorinated product); floors are slippery throughout the operation (signage, access closed); polishes are low-hazard but must be stored above freezing.

Robotic scrubbers on sealed floors

An autonomous floor scrubber maintains a sealed floor very well, on three conditions, and they are the same as for an operator-driven scrubber-dryer: a neutral detergent, correctly dosed, never alkaline; moderate brush pressure with soft brushes or pads, set during the demonstration; and a route plan that keeps the machine off freshly treated areas for 48 to 72 hours. In return, the robot delivers what extends a seal most: consistent sweeping and washing, with no abrasive soil left lying from one day to the next. On our PVC and thermoplastic sites, restoration stays with the team and the single-disc machine, and the robot takes the floor back as soon as it has cured. Our page on robotic industrial cleaning and the guide to floor cleaning techniques place sealing among the other restoration methods.

The sealing method sheet (PDF)

Free to use, no sign-up. A method sheet covering the floors concerned, the seven steps from stripping to the final coat, maintenance and spray buffing, the signs that call for restoration, common mistakes and safety. Download → (PDF, in French) All our templates are gathered on the downloadable cleaning templates page.