Tatami rooms are a wonderful part of many Japanese homes. They are elegant and stylish.
But look up “Japanese tatami room” in any Japanese DIY handyman’s manual and within the first few paragraphs, any guide will likely mention the notorious requirement for constant care, cleaning and replacement of materials in order to maintain their appearance.
Most materials used in the construction and decoration of traditional tatami rooms are natural fiber products, including raw pine wood, rush fiber and rice paper. The rooms look and smell great when they are fresh and new, but deteriorate, yellow and mould with age.
Earlier, we provided tips for renewing aged and discolored rice paper on the Japanese Shoji paper doors of tatami rooms. Now we turn our focus to replacing tatami floor panels – a larger, more expensive and somewhat more involved renewal job.
Traditional tatami floor panels are usually made from neatly woven mats of rush fibre (ie: Igusa plant) stretched over and sewn onto thick blocks of compacted straw from the same plant.
In recent years, lighter weight, synthetically backed tatami flooring panel alternatives have also become available. Some are often considered significantly inferior by traditionalists, but they do have benefits.
The newer alternatives use a high density Styrofoam backing instead of the compacted rush fibre. In general, they are often lighter, easier to transport and far less prone to going mouldy.
Most traditional tatami panels can be ordered as a standardized size. The rectangular dimensions of a single panel are 79.5 inches (~176cm) long by 34.5 inches (~88 cm) wide, plus or minus approximately half an inch (~1 cm) either way. They have a consistent 2 inch (~5-6cm) depth. Being of standard size, Japanese room sizes are commonly referred to by the number of tatami panels which fit onto the floor plan: 4 tatami, 6 tatami, 8 tatami mats, and so on. Manufacturers also offer custom made non-regular sizes of (traditional) tatami mats so they can be fitted around modern room fixtures.
The surface weave of any newly purchased tatami panel has a distinct green coloring and the sweet, natural scent of freshly cut straw. These characteristics fade in the months following installation as the fibers dry and harden.
Eventually, the straw turns yellow. A deeply yellowed floor is usually deemed old, worn out and in need of replacement, despite the physical condition or lack of wear or damage on the matting surface. Keeping a tatami flooring beyond moderate yellowing is the Japanese equivalent of keeping an outdated or sun faded carpet beyond it’s intended life in a western home.
The yellowing process usually takes approximately three to seven years, but can be extended slightly with a high level of cleaning and care.
Traditional tatami flooring provides a firm, yet soft, quiet and somewhat springy feel underfoot when installed properly. This is mainly due to tatami panels being made in two parts. The woven upper surface and the thick, sound absorbing lower fibre block both provide ‘give’ under weight.
International DIYers wanting to make a tatami room feel as close to the Japanese experience as possible, should be aware this the underfoot feel and the muffling of sound is extremely important in achieving the character of Japanese tatami rooms.
What is often called “Japanese tatami matting” by various international manufacturers and DIY outlets, is often only the thin upper portion of what’s used for a complete Japanese tatami floor panel in Japan. It is no substitute for the experience offered by full block panelled tatami. It would provide a very hard, uncomfortable and inferior floor in comparison.
In Japan, new tatami panels can be ordered and delivered from various tatami manufacturing workshops and DIY department stores as fully completed block backed panels. These are delivered ready for fitting by any eager handyman.
When professionally fitted, tatami specialists often perform the final stage of tatami panel fabrication at the customer’s home. They fit, trim and sew the fresh upper tatami weave to the lower compressed rush fiber block on-site.
Tatami come complete with a colored and patterned border (called heri). This neatens and finishes the edges of the panels.
Historically, the heri bordering of tatami mats had an important role in advertising social status and often depicted the zones of restricted access in the strict social structure of ancient Japan. Lower class citizens were often forbidden from entering tatami specifically colored for higher classed members of society. Commoners were excluded from areas designated for Samarai. Samarai were excluded from areas reserved for high priesthood. Priesthood was excluded from Royalty. And all were excluded from the zones reserved for only the Emporer.
This hierarchical meaning of the heri edging is generally no longer recognised in modern Japan and a range of colors and patterns are available to anyone wanting to coordinate their room. There is however, still some relationship between color, cost and perceived tatami quality. Royal reds and blues are usually always more expensive than browns and greens.
Tatami floors require good air circulation under and around the compacted fibres to prevent the growth of mould.
Tatami will deteriorate extremely quickly in high humidity environments without suitable aeration. Tatami is normally laid over rough and widely gapped floor boards in older wooden houses where air moves freely from beneath the building.
In modern buildings with well sealed cement floors, tatami panels usually sit upon a shallow pine or metal structure which supports the panels and elevates the floor (by approx. 1-2 inches).