How to clean a stone bath mat and make it absorb again

Step by step: how to clean a stone bath mat and make it absorb again

Safety first. Sanding a stone mat makes fine mineral dust. Always sand it wet, outdoors or in a well-ventilated space, and wear a mask. If your mat is old, unbranded or listed in a recall, do not sand or break it.

1. 1

   Shake off hair and grit

   Take the mat outside or over the tub and tap it on its edge to knock off hair, sand and dried soap flakes. Brush the underside too. Grit trapped on top grinds into the surface when you stand on it.

2. 2

   Wet the stone

   Run the mat under the shower or a tub faucet until the whole top surface is damp. Water loosens residue from the pores and keeps dust down. It will darken as it soaks up water, which is normal.

3. 3

   Spray with mild soap

   Mist the surface evenly with a little liquid dish soap mixed into water, or a gentle bathroom cleaner. Avoid bar soap and oily body wash, which clog the pores that make the mat work.

4. 4

   Scrub in small circles

   Work an abrasive sponge or stiff nylon brush over the surface in small circles, pressing harder on yellow or gray footprints. Turn the sponge often. Most surface dirt comes off in a minute or two.

5. 5

   Rinse until the water runs clear

   Rinse the mat thoroughly so no soap stays in the pores; leftover soap leaves a film that slows drying. Repeat the scrub if the surface still looks dull or patchy.

6. 6

   Wet-sand stubborn stains

   For stains that scrubbing won’t lift, dampen the spot and sand it lightly with medium-grit sandpaper, using gentle back-and-forth strokes. Stop as soon as the color evens out; you are only removing a thin layer. Rinse the dust off with water rather than brushing it dry.

7. 7

   Dry it completely on its edge

   Stand the mat upright against the tub or wall so air reaches both sides, and leave it for several hours or overnight. It is ready when the stone is back to its light, even color. A mat put down damp can grow mildew underneath.

Why a stone bath mat stops absorbing water

A stone bath mat stops working when its tiny pores fill with soap, skin oil and minerals. The mat is made of diatomaceous earth (diatomite), a porous mineral that wicks water off your feet and lets it evaporate fast. Once the surface is sealed with residue, water beads up and dries slowly.

Dorai’s care instructions say that lightly sanding a stained or slow area with medium-grit sandpaper restores the stone’s natural absorbency and quick-drying performance, and that the brand’s diatomaceous products should not go in the dishwasher. Dorai recommends cleaning about monthly. Other brands make similar mats, so check the card that came with yours.

• Keep body oils, lotions and bath oil off the mat. Step on it after rinsing, not after moisturizing.
• Do not use bleach or a strong acid such as a descaler. Mild soap is all the stone needs.
• Don’t soak it in a tub of water for hours. Rinsing is enough.

Is sanding a stone bath mat safe?

Sanding a mat from a known brand, wet and with a mask, is the method makers recommend. The caution is about dust and about where the mat came from.

In late 2020, Japan’s Consumer Affairs Agency recalled several diatomite products because they contained asbestos, and bath mats are one of the most common diatomite products sold. Asbestos is only a hazard when its fibers are released, and the EPA explains that fibers get into the air when an asbestos-containing material is disturbed. Sanding, cutting or breaking a contaminated mat would do exactly that.

• Buy from brands that name their materials and testing, and keep the product card.
• If your mat is cracked, crumbling, unbranded, or appears on a recall list, stop using it. Do not sand it or snap it to fit a bin; seal it in a plastic bag and check your local rules for disposal.
• Sand only wet, outdoors or with a window open, and wipe or rinse the dust away instead of sweeping it.

Stone mat or fabric mat: which is easier to keep clean?

A stone mat needs less frequent cleaning but more care with what touches it; a fabric mat needs washing every week or two but forgives anything.

A stone mat fits into a regular bathroom routine like the one in our bathroom cleaning checklist.

Mistakes to avoid

• Putting the mat in the dishwasher, which its maker says not to do.
• Cleaning it with bleach, vinegar or a descaler instead of mild soap.
• Dry-sanding it indoors and breathing the dust.
• Using it straight after body oil or lotion, which seals the pores.
• Laying it flat on the floor while still damp, so mildew grows underneath.
• Sanding hard over the whole mat when only one spot is stained.