How do you clean a marble floor without scratching it?

The Mohs scale ranks minerals by their ability to scratch one another. Two figures are enough to understand it:

• Calcite, the main constituent of marble and travertine: hardness 3.
• Quartz, the main constituent of sand: hardness 7.

A four-point gap on this scale is not a nuance: quartz scratches calcite without effort, systematically, on every contact under load.

It is not visible straight away. A grain crushed underfoot does not leave a scratch but a microscopic groove. Multiplied by thousands of footsteps, these grooves scatter light instead of reflecting it: the floor does not look scratched, it looks dull. And it turns dull first in the centre of rooms and in corridors, while the edges stay glossy.

Practical corollary: cleanliness and preservation are the same subject. Removing the sand removes the tool.

It is the most effective device, and the most neglected.

Length. A visitor needs to take at least three strides on it, roughly 1.2 to 1.5 metres. A 40-centimetre doormat traps only a fraction of the sand and gives a false sense of protection. On a busy villa entrance or building lobby, use two: an outdoor studded mat for the coarse particles, an indoor absorbent-fibre mat for the fine dust and moisture.

Upkeep. A saturated mat is a reservoir of abrasive: it redistributes what it has trapped. Vacuum or shake it out at least once a week, more often in windy periods.

The entry points people forget: the terrace door, the garage door, the pool exit, and the service door. That is often where the most sand comes in, because nobody has put a mat there.

On a handover site, this is set up before the keys change hands, not after — see the protocol applied on a villa.

The order decides everything. Running a damp mop over a sandy floor is the same as spreading an abrasive paste across the whole surface, with the added pressure of the handle.

The sequence that protects the floor:

1. Dry dust removal — dry microfibre mop, or a vacuum with the brush head raised. Microfibre fibres trap the particle instead of pushing it, unlike a stiff-bristle broom.
2. Visual check of the floor: no visible grit left before it gets wet.
3. Wet wash with a well-wrung mop, neutral product dosed at around 1%.
4. Drying of any areas left damp.

The pace depends on the city more than the property. In Marrakech, in a through-draught flat or one close to an unsurfaced road, dry dusting is a daily task. The rest of the maintenance routine is covered in our article on the routine care of marble and zellige (a traditional Moroccan mosaic tilework).

Safe to use without reservation

• Microfibre mop head and cloth, for washing as well as drying.
• Two-compartment bucket: one for the clean solution, one for the wrung-out water. A single bucket puts rinsed-off sand straight back into circulation.
• Vacuum with the brush head raised, or a soft-bristle parquet attachment.
• Soft rubber-bladed squeegee to push back a puddle.

Forbidden on a polished surface

• Green abrasive pad, scouring sponge, scouring cream, powder: they dull the shine in a single pass, and the treated area stays lighter than the rest of the room.
• Stiff-bristle broom: it pushes the sand instead of trapping it, and makes it grind against the surface.
• Vacuum with a retracted brush head, whose plastic nozzle rubs directly on the stone, or with hard castors loaded with grit.
• Steam cleaner in routine use: the heat and pressure serve no purpose on a polished surface and weaken a grout joint.

A case apart: steel wool. It is banned from routine cleaning; it only turns up in crystallisation, used with a high-speed rotary machine and a crystallising compound. That is work for a stone specialist, not something to try at home — and not every floor can be crystallised.

The second source of scratches, after sand, lies in what is placed down and what is moved.

• Felt pads under every leg, chairs and stools included. A dining chair is pulled out several times a day: it is the most damaging piece of furniture in a home.
• Monthly check of the pads. A worn felt pad that exposes the nail or the plastic underneath does more damage than no pad at all, because nobody is on guard against it any more.
• Soft castors on office chairs, or a protective mat. A hard castor concentrates its whole weight on a few square millimetres.
• Never drag furniture: lift it with two people, or slide cardboard under the feet.
• Bare metal feet on designer furniture: steel-on-calcite contact marks the floor the first time it is moved.

On a stone terrace or poolside, add outdoor furniture, which builds up sand under its feet — see treating outdoor areas after building work.

A floor that has just been crystallised is not fragile, but it is judged: this is the period when you compare it every day, and a scratch stands out on a surface that has become perfectly reflective again.

The instructions to follow, and to get in writing from the specialist:

• No acidic product, even diluted, even one labelled "stone-safe": limescale remover, descaler, vinegar. A single application is enough to leave a dull halo.
• No wet mopping with plenty of water for the first few days; a well-wrung mop only.
• Entrance mats in place from the moment the keys are handed over, not a fortnight later.
• Pads fitted before furniture is put back, not after.
• Systematic drying of damp areas in the kitchen and bathroom, given how hard Marrakech's water is.

What remains possible, and what no longer is: a superficial micro-scratch fades on the next crystallisation; a deep scratch, an acid halo or a step between slabs can only be corrected by sanding through a series of grits, as explained in our article on the difference between the three treatments.

After building work, EPUREVA's post-construction clean treats marble at 30 MAD/m² incl. VAT, with a method suited to the material; the full list is on the post-construction price list.