In this chapter in the “how to live in a Japanese apartment” series we talk about how to clean tatami as part of your regular household cleaning and what to do if you have a problem with mold or mites (dani).
What is Tatami?
Japanese-style rooms (washitsu, 和室) have flooring made of tatami mats, which are mats made from dried, woven rush reeds covering a hard compact straw core. Tatami has a smooth surface and is both springy and firm.
Vacuum Along the Grain
As part of your regular household cleaning, the easiest way to clean tatami mats is to use a vacuum cleaner. Because tatami mats are delicate, vacuum along the grain or you may damage the surface of the mat.
For Deeper Cleaning Wipe with a Dry Cloth
After vacuuming, you may also want to wipe down the surface (along the grain) with a dry cotton cloth.
You should avoid cleaning tatami with a wet cloth because tatami mats are highly absorbent and any retained moisture may cause mold to grow. A wet cloth may also remove some of the natural surface oils which help protect the mat from aging too quickly.
To prevent bad smells from wafting from your tatami, use a cloth to wipe down your mats with a small amount of regular vinegar. There are also commercial products for cleaning tatami mats, called 畳用クリーナー (tatami-yo- kuri-na-).
How to Prevent Mold From Growing in Your Apartment
If your apartment is not well ventilated it can be very susceptible to mold, especially during the rainy season and humid summer months. Here are some things you should do to help prevent mold growth.
- Remember to open air vents, leave your windows slightly open, and use a fan to circulate air in your apartment.
- Wipe your windows, window frames, walls, and tatami mats with a dry cloth to keep moisture down. Daily if possible!
- Use a de-humidifier (called a joshituki, 除湿機)
- Ventilate your bathroom after you shower or bathe. Some people even recommend leaving your bathroom fan running all day to help with air circulation.
- Put disposable de-humidifier packs in your closets and the corners of your room.
- Regularly check for mold, especially in the north corners if your apartment, in the back of closets, and around window frames.
If you do these things, you will likely not have a mold problem in your apartment. However, since we talking about caring for tatami mats in this article, we have to discuss what to do in case you do have a tatami mold problem. Here is an example of a mold-infested tatami mat.
How to Get Rid of Mold From Tatami
If you discover mold growing on your tatami, obviously, it is best to try to get rid of it before the problem gets worse.
As recommended to us by Japanese friends (and their moms!), the tried and true method to get rid of mold on tatami is to scrub it with ethanol (エタノール), using a small toothbrush.
You can also use a commercial product called Kabi Kira (カビキラー), literally “mold killer”. This is a spray that works great to get rid of mold on walls and bathrooms. However, Kabi Kira contains bleach, so be careful what surfaces you spray it on.
Dealing With Mites (Dani)
Dani (ダニ) are mites that live in tatami mats. They can be a problem in very old apartments and Japanese-style rooms where the tatami mats have not been replaced for a long time.
In almost all cases, the landlord or property manager will change the tatami mats every time a new tenant moves in, so as rule, you should not worry about dani. However, here are some pointers, just in case.
Dani usually strike while you are sleeping. You will know if you have a dani problem if you have small, red, and very itchy bites on exposed parts of your body, usually around your ankles, wrists, and neck.
To keep dani from infesting your tatami mats, take care of your mats, as we described above.
You can also use a bug spray called Dani Aasu （ダニアース) that is specifically made to use on tatami mats.