Tatami are made of a tightly-packed core, a rush cover, and two cloth borders. Detail of core. Detail of cover
Decorated goza mat.
In the Japanese home tatami mats are used as a surface for sitting, sleeping, and walking on. Light enough to be carried by an adult, mats are composed of a thick rice straw core, a soft reed cover, and two borders of cloth or synthetic tape which protect the sides. Tatami are approximately 3 feet by 6 feet, about the size of a single bed, and l 3/4-2 1/2 inches thick.
How to install Tatami mats
Tatami evolved over a long period, first beginning as a thin, easily folded straw mat on which people sat or slept. Later, more layers of rice straw were added to the core for comfort. A new function of these fortified, but still portable, mats was to indicate differences in rank, the most exalted members being given the privilege of sitting on tatami while others sat on the wooden floor. Tatami eventually came to cover the entire floor and are now a standard item in Japanese-style rooms.
A standing person takes up half a mat; a sleeping person, a full mat.” As this saying suggests, a single tatami mat accommodates two standing people; thus if two mats are placed together, there is just enough room to seat four to six people around a small table. Since this is perfect for playing cards or for doing flower arrangements, an initial purchase of two mats is recommended. More mats can be added later, following the patterns suggested on the following page.
When it comes to laying several tatami down together, one has to take into account the way in which they reflect light. Since the rushes used for the cover are not very long, they are wound laterally across the width of the mat in close parallel lines. The reflection of light varies according to the placement of the mats. Thus, some tatami will appear light, and others, dark, in the same room. The interesting patterns created add to the attractiveness of tatami.
Tatami provide a convenient way of estimating the size of an apartment or house in Japan. What is decided at the planning stage is the number of mats per room—41/2, 6, 8, etc.—and the area of each room is subsequently referred to by this number for example, a six-mat room, an eight-mat room, and so on. In real estate advertisements, the scale of an apartment or house is indicated in this way, providing one with a good idea of size and layout. Despite its importance in the Japanese conception of space, however, tatami are not the module for building proportions as is widely misinterpreted, and in fact, there are a number of “standard” sizes, as well as the practice of tailoring tatami to the available floor space.
In addition to tatami there is also available just the soft reed cover which forms the top layer of tatami. Called goza, these can be used in the home to create a tatami-like atmosphere or outside as beach mats.
Newspapers or plastic sheets are placed between the floorboards and tatami to reduce dampness.
So far we have only looked at tatami as something to sit on. But, originally, tatami placed on top of the floorboards formed a surface which was raised one level above the rest of the floor. A relic of this is seen in the tatami alcove where a small tatami platform, one or two mats high, is constructed in the corner of a room, on which flower arrangements or pottery can be exhibited. In this way tatami can be used either as a Japanese-style floor or as a display platform.
By piling two or three tatami on top of each other, a bench can be created. This novel use of tatami may have been first used during the Edo period (1615-1868). In 1857, on the occasion of his audience with the shogun, the then American consul, Townsend Harris, found himself perplexed as to whether he should or should not take off his shoes, and whether or not he should sit on the floor. In the end, Harris changed into a new pair of shoes at the entrance, and thus became the first and last person ever to enter Edo castle with his shoes on. The shogun, for his part, was seated upon seven tatami piled on top of each other. The height of this, about 16 inches, was roughly the same as that of an ordinary chair.
This kind of tatami chair or bench, still novel today, can be converted into a low table to be used with a small stool. Should one decide to use tatami this way, the ideal height would be about 12-18 inches. It is advisable to add a wooden frame or some kind of border to protect the edges from fraying. When used as a kind of bench, small flat cushions should be placed on it; when converted into a desk, the use of a tray is recommended. These not only help to protect the tatami but also add a decorative element.
In Japan there is the notion that tatami are to be used only inside the house. It is not, however, absolutely necessary to confine their use to the interior. It is possible, for example, to use tatami, instead of wood or bamboo, for the veranda, or outside on the lawn as a platform for a picnic or an outdoor concert.
Tatami can be used to floor a mobile home or camper. They can then be carried outside and used as mats or as a substitute for beds. In fact, in the past, trains and ships in Japan had sections provided with tatami for the comfort of passengers.
Tatami are surprisingly durable and easy to clean, requiring only a damp cloth or vacuum cleaner with a special brush attachment. Shoes or even house slippers are not worn on tatami, and furniture with slatted or barred legs is recommended to prevent marks from being made on the tatami. It should be noted that tatami are neither fire-resistant nor stain-resistant.
In most homes tatami are aired and dried out once a year in the spring. The straw core will last for many years, but the outer reed will need to be changed every few years by a professional tatami-maker.
Although tatami may be used outside, there is one point about which care should be taken: if exposed to sunlight, they will turn yellow. Furthermore, the straw and rushes will shrink, eliminating the layers of air inside, and begin to mold if tatami become too damp. Thus it is important to bring the tatami indoors after use. This has become less of a problem recently, since the use of a polystyrene filling has made tatami more moisture-resistant, but care should be taken nevertheless.