What are Tatami Mats? 15 Things You Need to Know

by David McElhinney | LIFESTYLE

If you’ve ever been in a Japanese home, temple, or even some stores and offices, you will have come across the Japanese tatami mat. Soft underfoot and with a unique woody fragrance, it’s no wonder tatami remain so popular in Japan. But what exactly are they, how are they made, and how can you use them? Read on to find out everything you need to know about tatami mats.

1. What are Tatami Mats?

Japanese Tatami Mats, Photo by Victor He

The word tatami comes from the verb tatamu (畳む, “to fold”, “to pile”). Tatami mats first appeared in the oldest Japanese book, Kojiki (Record of Ancient Matters), as far back as 712. The name derives from the fact that tatami mats were originally thinner and could be folded or piled up.

Through most of Japanese history, the floor itself would be made of wood, and tatami mats would serve a particular purpose such as seating, in the houses of the well-to-do. Over the centuries their use widened. By the Edo period shoin-zukuri rooms, that we now call Japanese-style rooms, had become quite common, where nobles and samurai slept on tatami or woven mats named goza (茣蓙), while common people used straw mats or even loose straw for bedding.

Shoin-zukuri rooms were characterized by coffered ceilings, shoji screens, square pillars, and tatami floors. Tatami mats were installed on the entire floor of a room. These areas were called zashiki (座敷, “spread out for sitting”) and the arrangement of tatami mats in the room was determined by strict rules.

In the sixteenth century, Sen no Rikyu (1522-1591) established the Japanese tea ceremony in small tea rooms featuring natural materials, including tatami floorings. Rikyu’s smallest tea room, Tai-an, built in Kyoto in 1582, had a minimalistic surface of two tatami mats. Find out more with the Essential Tea Ceremony Utensils.

© Takaokaya, Japanese Futon — © Takaokaya, Japanese Futon

By the end of the 17th century, tatami floors had reached almost every home, which continues until today. Most Japanese houses have a few tatami matted rooms, including many modern city apartments. Even if Western-style bedding is popular, Japanese people often still sleep on a tatami mat with a futon, a thin mattress, on top. The rooms having tatami floorings and other traditional architectural characteristics are referred to as washitsu, "Japanese-style rooms". We highly recommend you experience Japanese hospitality and sleep on tatami mats when staying at a ryokan!

2. What Types of Tatami Mats are There?

Foldable Japanese Tatami Mat, available at Japan Objects Store

Tatami are typically differentiated by size and shape, quality of materials and applicability. Here are some of the most notable styles:

Size and shape: Most people think of tatami as rectangular, but square-shaped mats are also fairly common. Square tatami mats usually measure three feet by three (90cm by 90cm) and can accommodate the modular, symmetrical design of traditional Japanese rooms. Rectangular tatami tend to be favored, however, because of their streamlined, elongated appearance which creates a larger sense of space and works well in unconventionally shaped rooms. They also allow for interlocking designs and patterns that are deemed auspicious in traditional Japanese culture.

Materials: Igusa rush grass and rice straw are among the most common materials used for tatami construction. The former is the gold-standard, known for its elasticity, longevity and ability to maintain its natural color. Igusa rush tatami mats also have a natural wetland fragrance and vaunted antibacterial properties. This is not to say that rice straw tatami always pale in comparison. These mats have a slightly rougher texture and golden hue, but are often firm, durable and have good insulation.

Applicability: Traditional tatami mats were rigid, laid down on the floor where they would likely remain until the end of their days. Modern adaptations have appeared to allow tatami to be used in different and creative ways. Foldable tatami are a great example. Though they can be used for sleeping, they also double up as a kids play area, a yoga mat, or for lounging around on lazy Sundays. Tatami rugs are also becoming popular. These mats have similar malleability to a Western-style carpet and can be used underneath a coffee table or in the middle of a living room.

3. How Big Are Tatami Mats?

Traditional Japanese Interiors, Photo by Jack Zhang

The traditional sizes of tatami mats differ between regions in Japan. In Kyoto kyoma tatami (京間畳) measure 0.95m x 1.91m (3 feet 13 ½” x 6 feet 3 ¼”).

Nagoya’s in-between size or ainoma tatami (合の間畳) measure 0.91m x 1.82m (2 feet 11 ¾” x 5 feet 11 ½”)

In Tokyo edoma (江戸間) or kantoma (関東間) tatami measure 0.88m x 1.76m (2 feet 10 ¾” x 5 feet 9 ¼”)

Due to the widespread use of tatami mats as the preferred flooring throughout Japanese history, they came to be the standard unit for determining room size. Rather than meters or feet, jo (畳) is used to measure the size of a room by calculating how many tatami will fit in it. For example, a tea room of 4.5 jo is large enough to fit 4.5 tatami. Both full-size and half-size mats (半畳, hanjo) are common. If you go apartment hunting in Japan today, you’ll come across this measurement

4. How are Tatami Mats Laid Out?

There are rules concerning the number of tatami mats and their arrangement in a room. In the Edo period, auspicious (祝儀敷き, shugijiki) and inauspicious (不祝儀敷き, fushugijiki) tatami layouts were clearly distinguished. The tatami mats would be rearranged depending on the occasion.

Nowadays, an inauspicious arrangement, in which the tatami junctions form a cross, is said to bring bad fortune. Evenly patterned grids are inauspicious. The only exception to using a grid pattern is during times of mourning.

Consequently, an auspicious tatami arrangement is where no four corners of any full-size mats touch is the ideal. The aim is to have the junctions of the tatami form a T to ensure good fortune. An auspicious arrangement often requires the use of half-size mats.

5. How to Use Tatami Mats?

Despite the modernization of Japanese houses, many Japanese people still enjoy a tatami floor and find it comfortable. Recently, tatami mats for placing on wooden floor have become more common. If you wish to add a Japanese touch to a Western room, you can enjoy the feel of tatami with mats such as these.

Tatami manufacturers now diversify their products and offer such items as tatami yoga mats, tatami play rugs for kids, miniature tatami mats, foldable tatami mats and even tatami shoe soles.

6. What are the Benefits of Using Tatami Mats?

Sleeping on tatami mats can be an acquired taste. But given the range of benefits, it’s definitely worth considering.

Comfort: Tatami mats provide a comfortable and soft surface to sit lie, or sleep on, particularly if you’re accustomed to sleeping on your back.

Insulation: Tatami mats have insulating properties that help to regulate room temperature. They also adapt to the season, providing warmth in winter and a cool surface in summer.

Aesthetics: Tatami mats are distinctly Japanese and will feel at home in a washitsu (Japanese-style room) or any other room with an East Asian design theme.

Health Benefits: The natural materials in tatami, such as rush and rice straw, regulate a room’s humidity and are therefore said to benefit the human respiratory system.

Versatility: Tatami mats are incredibly versatile. You can use them as soft flooring in the bedroom, for sitting around a coffee table in the living room, as private meditation or mindfulness spaces, or if you want to be extra refined, in a traditional tea room.

Environmentally Friendly: High-quality tatami mats are made from natural, biodegradable materials, making them easier to recycle or dispose of with minimum environmental impact.

Low Maintenance: Tatami mats are fairly easy to maintain. General guidelines suggest they need occasional sweeping or vacuuming, followed by sun drying to keep mold and dust mites at bay.

7. Where Can I Buy Tatami Mats? And Can I Get Tatami Mats Outside of Japan?

Tatami Mats are available at the Japan Objects store, including this Rush Grass Foldable Tatami Mat made in Japan’s southern island of Kyushu. Pairing nicely with a Japanese futon, it enhances sleep comfort with its soft yet supportive underlay. Its portability also makes it particularly utilitarian, so feel free to reapply it to a meditation corner in your home or nestle it by a bay window and gaze out at nature on summer evenings.

8. How Can You Tell The Quality of Tatami Mats?

The two major indicators of tatami quality are where it’s made and the materials used. Many mats on the market are now made in China. Some of these have risen in quality in recent years, thanks to Japanese companies extoling knowledge to Chinese producers. But a tatami mat made in Japan is the official seal of quality.

The use of natural materials is equally important. Not only will they give you a better experience for longer, but the mats will also be more comfortable, environmentally friendly, and carry a pleasant natural scent. If a tatami mat is very cheap, it’s likely been made with synthetic materials like polypropylene, PVC, or other synthetic fibers.

9. Can I Use Tatami Mats on Hard Floors or Carpet?

Tatami can be placed on hard floors, like stone or heated wood, or on top of carpets. As long as the floor isn’t prone to damp or high in humidity, you shouldn’t have any issues. If you’re using tatami on top of a carpet, however, it’s best to use a foldable type as these mats are easier to remove, air and clean. If in doubt, use our tatami care guidelines to help you decide which surface will mitigate moisture and maintenance issues.

10. Are Tatami Mats Suitable For People With Allergies?

If you’re allergic to dust mites, you’ll need to exercise extra observance when searching for a tatami mat to buy. Some are prone to dust and mold, others are treated in such a way to be dust mite-resistant.

The material composition of the mat is important. Mats made from natural materials like igusa rush grass or other plant fibers tend to have inherent properties that make them less attractive to dust mites. Some modern synthetic tatami mats are also designed to be resistant to dust mites, but be sure to check the product description before purchasing. One thing to look out for is antimicrobial treatments. Mats in this category are treated with agents during the manufacturing process that help prevent the growth of microorganisms.

11. Can Tatami Mats Be Used Outdoors?

The simple rule is not to use tatami outdoors in humid or rainy climes. Excessive moisture and damp is the death knell for any kind of tatami mat. In dry climates, you can use tatami outdoors, but be sure to bring in the mat immediately when the rain starts or be or dry it out fully when wet. Its best not to leave a tatami for too long on a surface prone to moisture like grass or wooden decking. Some waterproof tatami mats for outdoor picnics or sunbathing on the beach have landed on the market, but they tend to be of mixed quality.

12. How are Tatami Mats Made?

© Igusa Photolog, Bunches of Igusa Grass

The basic structure of a tatami is simple, comprising a base (doko), a cover (omote), and a border (heri) crafted into a rectangle.

The base (doko) is traditionally made of multilayered natural rice straw, tightly attached, and compressed. A natural base is the best choice, the most economical option in the long term and has been used for centuries. Its key characteristics are durability, fireproof properties, humidity control, resilience, and thermal insulation. The feeling barefoot is unique.

There are various grades of base; the more natural material used determines the cost and quality. As the grades of base differ, so does the straw (gomoku, crushed straw) included in the base. The best quality is used in shrines, tea rooms, and temples, while the multipurpose base is popular for apartments.

Samples of Tatami in Japan by se7en on Creative Commons

Nowadays, the base now also can be made of light materials like Styrofoam, inserted between compressed wood-chip board. The feeling is similar to the natural base but it is harder and less durable. It is nevertheless cheaper, lighter, with a better insulation and more resistant to moisture and bugs.

The cover (omote) is made of woven natural soft rush straw (藺草, igusa). As with the base, the highest grade of cover is generally employed in shrines, temples, and important spaces.

A high-quality cover has four hemp strings, two at each weave, binding the straw together. A stronger string makes the surface thicker and affects the feeling underfoot. The rush straw used in these mats is only harvested once a year.

High to mid grades are often used in Japanese and international homes. Lower grade cover is a good choice for areas of high use like apartments for rent, where mats will need to be resurfaced more regularly.

You may find cheaper tatami covers outside of Japan, but their quality tends to be questionable. We strongly recommend purchasing made-in-Japan tatami mats.

Brand new tatami flooring has a light green color and smells like fresh grass. The scent goes away in a few weeks. The cover gradually turns light brown with age, and its color comes to match nearby wooden interiors.

Tatami mats work well with the climate of Japan, humid and hot in summer and dry and cold in winter. Tatami flooring increases quality of life in terms of acoustics, air quality, and humidity. They act as sound and temperature insulation, and they filter the air in a room and absorb carbon dioxide. The rush weave cover regulates humidity: it absorbs or expels moisture when the seasons change.

Tatami borders (heri) used to be made of cotton or hemp. Nowadays, synthetic borders are cheaper and stronger, but in terms of quality, natural fiber is always better. High class borders are made of hemp. In the past, depending on the formality of the room and the wealth of the owner, this border might even be made of silk brocade.

© Jackson Boyle / Creative Commons, New Tatami Mats

Borders can feature a solid color or traditional Japanese patterns, especially used for temples and tokonoma (alcove). Since tatami borders are durable and beautiful, their fabric may be used in products like bags and pouches.

13. Where Are Tatami Mats Made?

Like most craft forms in Japan, tatami production has various heartlands littered throughout the country. Kyoto, the nation’s arts and craft capital, is, of course, a hub of tatami mat artisans. Workshops like Yokoyama, run by eponymous tatami maker Mitsuru Yokoyama, build on years of tradition to craft mats for traditional Japanese homes and design projects globally. Yokoyama’s work has been featured at Ise Jingu, one of the oldest Shinto shrines in Japan, as well as at Kosei-in Temple, the G7 Summit, and in various exhibits throughout Europe, North America, Africa, and Aisa.

In Japan’s southernmost main island, Kyushu, there is also a rich tatami tradition. Producers like Ikehiko, founded in Fukuoka in 1886 before expanding across the country, utilize high-caliber igusa rush grass, which is known for its durability, comfort, environmentally friendly properties, and natural aroma. Higashiizu is a smaller, but no less respected, haunt for tatami artisans. Multi-generational producers, like Tokiwa, in this small town on the Izu Peninsula supply the local ryokan and architectural projects elsewhere in the country with high-grade tatami mats.

Some Tatami producers also provide workshops to tourists. At Fujitami Guesthouse in Osaka you can make small tatami art with a local artisan. At Yamada Tatami in Kyoto you can watch a pair of expert craftsman ply their trade. Or head to Shizuoka City and make miniature tatami coasters and tatami photo frames with legendary tatami maker Tomoyuki Kameyama.

14. How to Take Care of a Tatami Mat?

© blieusong / Creative Commons, Tokanoma Alcove

The easiest way to clean tatami mats is to use a vacuum cleaner. It is important to vacuum along the grain or one may damage the tatami cover. After vacuuming, it is possible to wipe the surface along the grain with a dry cotton cloth.

One should avoid cleaning tatami with a wet cloth. As tatami mats retain moisture, this may cause mold to grow. A wet cloth may also eliminate some of the natural surface oils which help protect the mat from aging too rapidly.

A well-ventilated room is important for tatami: open windows often or use a fan to circulate air. Furniture may be placed for long periods on the tatami floor, it will resume its shape once the furniture is moved, due to the air ventilation in the base.

Tatami mats can be renewed if the old rush flooring needs to be replaced. This process is named tatami no omotegae (change of tatami cover). People usually ask for this procedure at tatamiya san (tatami repair shops).

15. How Long Does a Tatami Mat Last?

As you’ve likely guessed, this will depend on the quality of the materials. If you purchase high-grade, and look after the mat well, you can expect to get 50 years out of it. With cheaper man-made materials, this might be slashed to about 25 years – still not a bad return. Just remember that durability is one of the chief selling points of tatami. The conventional wisdom suggests that even the cheaper options on the market will last longer than your average carpet.