Tatami mats are traditional Japanese flooring mats. They are of a size that permits a person to lay down and sleep upon them, with the top surface covered by goza (straw mats) that are weaved with rice straw. A tatami mat’s thickness is, when following convention, either 55mm or 60mm (about 2.2 to 2.4inch). Although tatami mats are used for flooring, due to the igusa (soft rush) with which they are made they exhibit considerable cushioning properties.
Within Japanese homes, tatami mats are laid upon the floorboards. As rooms that will be laid with tatami mats are constructed to a size that will allow a precise fit, it is possible to completely cover the floor with them. The size of a tatami mat can vary considerably depending on the region and period: in the Kanto area, 176x88cm (about 69x35inch); in the Kansai area, about 191×95.5cm (about 75x38inch). Apartment buildings typically use a size of 170x85cm (67x33inch).
Incidentally, in Japan, the size of a room is expressed in the number of tatami mats. A room fitting six tatami mats would be a 6-mat room, and a room fitting four-and-a-half tatami mats would be a 4.5-mat room. On the flooring plans found on the leaflets of real estate agents, room size is written as a simple number, such as “6” or “8,” showing the number of tatami mats that can be fit. Even the size of rooms that have bare flooring with no tatami mats are expressed in this way.
In Japan, when entering a house, it is customary to remove one’s shoes. With shoes or slippers taken off, tatami mats are walked on either with bare feet or just socks. Due to the cushioning properties of tatami mats, they can be sat on or slept upon directly. However, ordinarily, a cushion such as a zabuton will be laid out when sitting down, and a futon or mattress when sleeping.
Various Types of Tatami Mat
There are various types of tatami mats, such as those with fabric edging and those without, as well as tatami mats made especially for the tokonoma (a type of alcove). The standard tatami mat in Japan is the type with edging (heri-tsuki tatami). Due to the fabric edging covering the easily damaged edges and corners, this type of tatami mat wears well. Moreover, there are a wealth of fabric patterns and colors available for the edging, offering options to suit the interior design of any room.
Edgeless tatami mats (heri-nashi tatami), which are mainly used in Okinawa Prefecture, are also known as Ryukyu tatami mats. These are square mats about half the size of a standard tatami mat. By combining mats of different colors and alternating the directions of the weave, it is possible to create a feeling more similar to western-style flooring.
Tokonoma tatami mats are, just as the name implies, made specifically for the tokonoma. In Japan, the tokonoma is a 1-mat large area for displaying things such as pictures, flower arrangements, and pottery, built a step higher than the rest of the floor in a corner of Japanese-style reception rooms. The tatami mats used here are for decorative purposes, using a gorgeous, traditionally patterned edging (mon-beri). However, as they are not made for everyday use, they are not as durable as standard tatami mats.