Don’t let this happen to you! Taking care of futons and tatami


Editor’s Note: A fellow gaijin friend of mine who lives in Hiroshima recently found out the hard way why it’s important to fold up and put away her futons each day. After searching her apartment for the source of a mysterious foul odor last month, she was horrified to discover a huge mess of disgusting black mold growing between her futon and a bamboo mat beneath it on the linoleum floor. Unfortunately, no one had thought to clue her in about proper care for her futon after her arrival in Japan last year, and she unwittingly left it laying out for a couple months without being aware of the breeding ground this would create for mold. Learn from her experience and don’t let this happen to you! To make sure everyone is aware of how to properly care for futons and tatami, we are reprinting an article that originally appeared in the Hyogo Times in June 2008. If anyone has any additional tips to share, please leave them in the comments!

By Jeff Morrice

This past winter you may have been cursing the Japanese and their lack of insulation, but you should remember that the Japanese house is designed to be a living, breathing organism.

The space beneath your abode allows air to circulate, and nearly everything indoors is designed with a purpose — your tatami regulates humidity and temperature, your paper shoji screens limit direct sunlight, and even your wooden fusuma (sliding doors) help to absorb and release moisture.

But as the seasons change and we head into the rainy season with the humidity steadily climbing, we need to make sure that our living houses are still in good shape. So here are some handy tips to get your house prepared for the summer humidity.

Futon Care

It’s recommended to air out your futons at least once a month, but once a week is better to keep them in top shape. Do it on hot, sunny days when there:s no chance of rain and remember to bring them in before sunset, otherwise they’ll absorb the evening moisture and be damp again in no time.

It’s also a good idea to beat your futons with a paddle to shake the dust out — less dust means less chance of mites and bedbugs setting up shop.

Beyond that, futons can also be washed in double-sized washing machines or at laundromats, or taken in for dry-cleaning. However if you do wash your futon, remember that it will take a long time to dry — probably a day or two in the sun — so have a spare futon to sleep on that night.

Lastly, take some time each morning to fold and put away your futons. Leaving them in the same spot on the tatami is a good way to grow yourself a new colony of spores. So unless you area  biology major doing a thesis on tatami mould, get those futons folded up every day!

Tatami Care

Believe it or not, tatami can be aired out as well. Tatami absorbs a lot of moisture naturally, which is a good thing as it regulates the moisture in your house, but the mats do need to be dried out every so often.

Unlike carpet, tatami mats are not a permanent installation and lift out of the floors relatively easily, meaning they can be taken outside on a hot day for air and sun. This should kill any mildew, bugs or mould colonies that you’ve been harbouring.

Some people air out their tatami every three months, some once a year, and some every seven years — it depends on humidity and laziness. Doing this once a year should be good enough for Hyogo and most other areas in Japan, but it doesn’t hurt to do it more often. It’s best to do this on a hot, cloudless day when there is no chance o f rain. If it rains on your tatami, you’ll be buying new mats, and they aren’t cheap.

Most tatami mats are also double-sided, and can be flipped (though with the lifespan of tatami usually averaging 14-15 years, rotating the mats is a rare task!). General tatami care should be followed before you air them out or flip them — wipe with a very slightly damp cloth to get rid of stains or spills, vacuum the mats with the grain and never walk on the mats with your shoes on.

Another way to fight futon and tatami humidity is with shikketori packets, which are those little ‘DO NOT EAT’ silica packs you find in new purchases. The shikketori pellets absorb moisture until they turn into a gel, and should then be replaced. They are great for closets, dresser drawers and clothing containers and the slim ones can also be placed under tatami mats and between tatami and futons. You can also get bucket-sized ones that are good for both closets and small rooms.

If you do happen to get mites in your mats there are sprays to take care of them. These aerosol cans come with special nozzles that plug into your tatami so  you just have to spray away and rid yourself of the pests.

Finally, if you consider yourself as rich as your students think you are, go out and get a dehumidifier. These can run upwards of 100,000 yen, but they’re unrivalled for keeping your house moisture-free. Also, hanging laundry in a room with a dehumidifier dries your soggy clothes in no time flat!


  1. Would having a rug in a tatami room also create mold like this? I put my futon away every day, but I do have a thin rug in the middle of the room covering up some floor stains left by my predecessor.

  2. Good question, Courtney. We have a carpet over the tatami in one room in our apartment as well, and I’ve been wondering about that too ever since this happened to my friend. Anyone know the answer?

  3. I would guess that as long as you air it out every now and then, you should be fine. The problems with futons are that they absorb moisture from you when you sleep on them, as well as skin, body oils, and dirty. Thus making them breeding grounds for mold.

    When I moved into my apartment there was a big dark spot on the tatami that was oddly the exact same size as a futon… in the exact spot where my pred would sleep…. It also was oddly the least gross thing about my old apartment when I moved in.

  4. Taking care of futons and tatami…

    Is your futon all moldy? Has your tatami seen better days? All of this could have been avoided if you’d just followed some simple cleaning rules….

  5. My floors are wood and there’s a thin carpet on top. I still found a bit of mold after leaving my futon untouched for a month. I don’t think the surface on which the futon makes a huge difference if it’s absorbing a lot of moisture. A friend of mine, a former JET whose now going on her tenth year of residency, told me that she has never once aired out her futon. She vacuums it regularly instead, which I found to be a great alternative during the winter months and the rainy season.

  6. That is so gross. It’s not even green or brown anymore, it’s BLACK! She must’ve noticed when her futon started to move by itself 😛 I’d still prefer a good bed to sleep on.

  7. Poor ventilation causes mold. I’ve never had bed bugs. Maybe it’s because I always keep a window open.

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