Frequently Asked Questions

What other size formats are there in Japan?
How heavy are these mats?
How do you clean spills and stains? Is sweeping or vacuuming better?
Will the igusa (rush covering) colour age? How about the special Japanese paper covering?
Does the grassy scent eventually fade away?
What to do if the covering is worn out through excessive use?
Are there mites and dusts in the tatamis? How do I prevent this?
Are there standard ways to lay the mats?

What other size formats are there in Japan?

There are a few traditional accepted sizes of tatami mats in Japan. Based on the shaku (尺), an old Japanese measure derived from the distance between 2 growth nodes on a bamboo, it is approximately 30.3 cm. Tatami mat lengths were originally the length between 2 pillars equal to about 6 shaku (尺), and strangely, the length of the shaku (尺) did vary from time to time until a standard length was decided upon towards the end of the 19th century.

Honma	The largest format based on 6.3 shaku (尺). Also known as Kyoma. Commonly found in the Kansai, Shikoku, Kyushu area. 191.0 cm length by 95.5 cm wide by 5.5 cm thick which covers an area of 1.8241 square metres. This is equivalent to 75.2" length by 37.6" wide by 2-1/4" thick, which covers 19.64 square feet of area.
Roku Ichima	Based on 6.1 shaku (尺). Found in some parts of the Chugoku region. 184.8 cm length by 92.4 cm wide by 5.5 cm thick which covers an area of 1.7076 square metres. This is equivalent to 72.76" length by 36.38" wide by 2-1/4" thick, which covers 18.382 square feet of area.
Chukenma	Based on exactly 6 shaku (尺). Commonly found in parts of the Nakagyo area in Aichi, Gifu, Mie Prefecture, Okinawa. 181.8 cm length by 90.9 cm wide by 5.5 cm thick which covers an area of 1.6526 square metres. This is equivalent to 71.57" length by 35.79" wide by 2-1/4" thick, which covers 17.7856 square feet of area.
Go-Hachima	Based on about 5 shaku (尺) and 8 sun (寸). Also known as Edoma. Commonly found in East Japan areas of Kanto, Tohoku, Hokkaido and gradually gaining nationwide standard. 175.8 cm length by 87.9 cm wide by 5.5 cm thick which covers an area of 1.5453 square metres. This is equivalent to 69.21" length by 34.61" wide by 2-1/4" thick, which covers 16.632 square feet of area.
The last standard is a cutout for the tatami mat, usually found in Japanese tea rooms.
Chashitsu Kirikomi	Based on 1.4 shaku (尺) 42.4 cm length by 42.4 cm wide by 5.5cm thick which covers an area of 0.1798 square metres. This is equivalent to 16.69" length by 16.69" wide by 2-1/4" thick, which covers 1.9344 square feet of area.

While we attempt to provide as many choices as possible, our stock size closely estimates the Honma format, which is the largest of the formats. If any special pieces are required, Tatami Imports will gladly take custom orders including custom sizes.

How heavy are these mats?

A full size tatami mat can weigh up to 30 kg (66 lbs). While there are lighter tatami mats these days that can weigh as little as 10-15 lbs, these are filled with a combination of compressed fibre board and insulation foam. Tatami Imports does not carry these tatamis as they are contrary to the idea of the tatami mat as an all-natural and environmentally friendly floor. Furthermore, insulation foam breaks down, compress and decompose with usage. Insulation foam is a petroleum by-product and is not environmentally friendly.

How do you clean spills and stains? Is sweeping or vacuuming better?

Spills and stains are dealt with like carpet stains. A dry cloth is first used to clean up the spill, then a damp cloth is used to clean up the stain. When cleaning, try to go along the weave, not against it. It does not matter whether you prefer sweeping or vacuuming, the important thing to remember for regular maintenance is to use soft bristles and to always go along the grain, not against it.

Will the igusa (rush covering) colour age? How about the special Japanese paper covering?

Yes. When delivered, the igusa will look fairly green (more so with the higher grades) in colour. The colour will eventually fade to a yellowish or whitish hue, especially if placed in direct sunlight. The paper will also fade but to a lesser extent.

Does the grassy scent eventually fade away?

No. You may be surprised that the natural grassy scent does not go away. While the owner may eventually be desensitized to the scent, only getting a whiff once in a while, visitors to your home will immediately pick up the scent even if the tatamis are over ten years old!

What to do if the covering is worn out through excessive use?

If that ever happens, just change the covers. You do not have to discard the whole tatami just because the covers are worn out. However, with the quality of our tatami mats, you will not have to do that for at least eight years. With care and maintenance, tatamis can last over 15 to 20 years.

Are there mites and dusts in the tatamis? How do I prevent this?

All our tatamis are manufactured in Japan and the materials are cleaned and disinfected before use. There is a paper layer that acts as a barrier if there are resident mites. Traditionally, the Japanese lay their tatamis out in the sun once a year as the sun's ultraviolet rays help eliminate these mites. However, regular vacuuming can and does help remove mites and dust as they do for regular carpets.

Are there standard ways to lay the mats?

No. Except for the Japanese tea room, which has accepted traditional formats, the tatami mat layout can follow any pattern possible.