How to Clean Tatami Mats

What tatami is and why it needs dry care

Traditional tatami mats have a core covered in woven rush grass (igusa), usually with cloth edging. The grass is natural and absorbent, so water can stain it, cause it to swell or discolor, and encourage mold. That is why advice from most sources is the same: clean with dry methods first, use as little moisture as possible, and dry everything promptly.

Mats vary. Some modern tatami uses synthetic or paper-based surfaces, or a different core, and these may be more tolerant of moisture. If you have the manufacturer’s care instructions, follow them over general advice.

If you sleep on a futon over tatami, see how to clean a Japanese futon as well. This is different from a washable rug. For rugs, see how to deep clean an area rug at home.

Safety first

Never mix cleaners. Bleach with ammonia, or bleach with vinegar or other acids, can release toxic gases. Avoid bleach on tatami in any case, since it can discolor the grass. If you use vinegar, use it alone and diluted.
If you use rubbing alcohol or ethanol on a spot, ventilate the room, keep it away from flames, heat and cigarettes, and keep it away from children and pets, because it is flammable and harmful if swallowed.
Mold spores can irritate the airways. Wear a mask and gloves when cleaning visible mold, and stop if anyone in the household has asthma or allergies and the mold is widespread.
Keep children and pets away from cleaning products and wet areas until the surface is dry.

Routine cleaning

Vacuum or sweep along the weave. Moving with the grain is gentler on the fibers than moving across it. Use a hard floor or soft brush attachment, or a hand vacuum. Turn off any spinning beater brush, which can catch and tear the grass.
Wipe with a dry cloth. A dry cotton or microfiber cloth, again in the direction of the weave, picks up fine dust.
Get into the gaps. Dust collects at the edges and seams. A soft brush or the vacuum crevice tool helps.

Doing this regularly, such as weekly, helps stop grit from wearing the surface.

Dealing with spills

Blot straight away with a dry cloth or paper towel. Press, do not rub, because rubbing pushes liquid deeper into the straw.
Keep blotting with fresh dry cloths until no more liquid transfers.
If the spot is still damp, press a dry towel over it and allow the area to air dry. A fan can help.
Lift solid spills carefully before blotting.

Spot cleaning grime

For a grubby patch, some sources suggest a mild solution of white vinegar and water, commonly around one part vinegar to three or four parts water.

Dampen a cloth with it, rather than spraying the mat directly. The cloth should feel only slightly damp.
Wipe along the grain.
Follow with a clean, dry cloth, and let the mat air dry completely.
Test on a hidden spot first, because natural dyes and finishes vary and vinegar can affect some of them.

Avoid wet mopping, steam cleaners, carpet shampoo and soaking. If you are unsure whether a product is safe, skip it.

Preventing and handling mold

Mold and mildew are the main hazards for tatami, and they usually come with trapped moisture and poor airflow.

Prevent it: Keep the room ventilated, and avoid leaving damp items, such as wet clothing or bedding, on the mats. Pull furniture away slightly from walls where possible, and do not let water sit.
Spot it: Look for white, green or black patches, or a persistent musty smell.
Small spots: Some guidance suggests gently wiping with a cloth lightly dampened with diluted vinegar or ethanol and a soft brush, then drying thoroughly. Work gently, wear a mask and gloves, and ventilate.
Larger or recurring mold: If mold is widespread, keeps coming back, or has grown into the core, this is a job for a specialist, and replacement of the mat may be the more reliable fix. Check what is causing the moisture.

Airing and humidity

Open windows regularly so air moves through the room.
Many sources suggest keeping indoor humidity moderate, around 40 to 60 percent, and a dehumidifier or fan can help in damp seasons.
Some people air out mats by lifting or propping them up on a dry day. Gentle, short exposure to sun is sometimes recommended, but prolonged strong sunlight can fade and dry out the grass, so keep it brief and avoid the harshest hours.

Pests and dust mites

Dust, crumbs and moisture can attract pests such as mites and insects. Regular vacuuming along the weave, airing, and keeping the room dry and clear of food are the main defenses. If you see signs of an infestation, such as fine powder, small insects or damage to the edges, a pest professional or the mat supplier can advise.

Is sleeping on a tatami mat healthy?

Many people sleep on a futon laid over tatami, and it is a traditional arrangement in Japan. There is not strong evidence that it is either harmful or particularly beneficial for health in general. Comfort is personal, and a firm surface suits some people more than others. If you have back pain or a medical condition, ask a health professional. From a hygiene point of view, the key is to keep the mat and bedding dry, so air the futon regularly and do not lay bedding on damp mats. If you also care for bedding, check each item’s label.

Jiu jitsu and exercise mats are different

Exercise and martial arts mats are usually foam or vinyl-covered, not woven rush grass, so they are cleaned with different methods, commonly a mild disinfectant or soap suitable for the surface, wiped down and dried. Follow the manufacturer’s guidance for the product. Note that tatami in the traditional sense should not be treated like those mats.

When to call a specialist

Widespread or recurring mold
Deep staining, or water damage that has reached the core
Insect damage
Old or valuable mats, or mats you want re-covered (the surface can often be replaced)

For general household mats such as those found in a car or doorway, see how to clean carpet floor mats.