Thatch: humble yet elegant roofing material in search of a new lease of life - Japan Today

2021-12-25 01:20:10 By : Mr. SG Derek

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In England and Denmark, there are still entire villages of thatched houses. While it is expensive to thatch a roof in those countries, it is not prohibitively so, and the tradition of thatching is very much alive.

In Japan, however, the era of the thatched roof is coming to an end. You can still see examples of thatching on the roofs of a few surviving temples, teahouses, farmhouses and cultural landmarks protected by the government. But the number of full-time professional thatchers still working in Japan can probably be counted on the fingers of two hands.

This is especially sad because thatch used to be the standard roofing material in Japan. It was used not only on farmhouses, but on the country's grandest buildings. For example, the most important Shinto shrine in Japan, the Grand Shrine of Ise 伊勢神宮 in Mie prefecture, has a thatched roof.

Several varieties of thatch are used on Japanese roofs. Most roofing thatch is made of susuki (芒) a high-growing grass with long, blade-like leaves and delicate seed fronds. Also known as Japanese pampas grass, it appears in countless screens and scrolls as the 'autumn grass’ so beloved of Japanese poets and painters.

When cut and bound to the roof of a farmhouse, Japanese pampas grass is called kaya (茅). Roofs thatched with kaya are more durable than those thatched with rice straw and can last for up to 70 years.

Another kind of grass used in thatching is shino (篠 dwarf bamboo), which is denser than kaya and is generally only used for the corners of the roof. It is cut in early spring, when the leaves fall off the dry stalks of bamboo.

Not all roofs are made from kaya. A roof thatched with rice straw is a warabuki 藁葺き. A roof thatched with rushes is a tomabuki 苫葺き. A roof thatched with cypress bark shingles is a hiwadabuki 檜皮葺き.

There are plenty of other variations on traditional Japanese thatching techniques, depending on region, budget and family tradition. For example, some thatchers like to create a slight upward curve at the eaves by inserting a layer of rice straw under the edges of the roof.

The history of thatch in Japan goes all the way back to the Jomon era (c. 14,000–300 BCE). Traditionally, every country village had a thatch field and thatch was harvested as a regular part of the farming calendar. It was stored in communal sheds, and everyone pitched in to help when a thatched roof needed to be replaced. Materials were plentiful, as was work for thatchers, so it was not expensive to thatch a roof.

But since WW2, rural homeowners have opted to use modern roofing materials, like tiles, concrete or plastic. The more popular these materials became, the cheaper they became. Conversely, as thatch fell out of favor, it became more and more expensive.

These days, thatching a roof costs so much - and thatchers are so rare - that homeowners with thatched roofs often choose to simply cover them with corrugated iron or even plastic sheets rather than pay to have them rethatched.

The Japanese countryside is changing. Every year, more young people from country towns and villages leave for the cities in search of work, and the average age of a farmer rises. In the future, the number of farmers is set to fall even further, and even more farmland will be abandoned.

Not all hope is lost, however. Every year, a steady trickle of incomers from the cities opt to turn their backs on city life and move to the countryside. The coronavirus pandemic has given fresh impetus to the phenomenon of the 'U-turn', though to what extent it will revitalise rural communities it's not yet possible to say.

Some of these urbanites, less in thrall to 20th century materials like concrete, steel and glass, and more appreciative of the beauty of traditional materials like timer, thatch and clay, are choosing to keep traditional crafts like thatching alive.

Thatch used to be considered the embodiment of elegance. Indeed, using humble materials to create sophisticated works of art is one of the defining characteristics of the Japanese artistic tradition. Perhaps the new generation will grasp this fundamental truth and put it into action.

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LOVE LOVE LOVE that particular design of roof- such a shame to see it go out of style

Just for some background, but a thatched roof in the UK lasts about 70 years before complete replacement. If the "Grand Designs" tv program can be believed, the modern way to do it is on plasterboard so that burning thatch can be raked off without falling into the house. If it did, the whole house would burn down in minutes. There is a similar lack of thatch in the UK, but you can truck it in from places like the Balkan states.

In Japan, with the extra humidity, a thatched roof will last about 30 years. That's with wood burning year round on an irori (open hearth) to send smoke through the thatch to preserve it from rot and insects. Having an open hearth with no chimney means your house is smokey and cannot be made airtight, lest its occupants die from carbon monoxide poisoning. You cannot thatch on plasterboard because it needs to be smoked, so the house remains a huge fire risk. They do look very pretty though, and the cost is not a problem if government grants are paying. I know none of this sounds very romantic, but sometimes the old way is not the best way.

Thatching a roof is also illegal in many parts of Japan.

When I bought my house in rural Chiba prefecture, one of the conditions of the purchase contract was "no thatching permitted".

There's no hope for a revival of thatching under the current regulations.

Thatch is very nice but expensive to replace and difficult to find the craftspeople to do it. Only banned on new builds because of fire risk.

OK, to thatch or not:

potential rot and insect infestation

needs smoke to prevent above

skilled repairmen limited in availability

can not seal house to prevent drafts/cold

looks nice, great for instagram

Thatch is very environmentally friendly, extremely insulating and it is utter rubbish that you need to have smoke going through it. Many, many houses in my village and up the valley are thatched and not a one of them has smoke going through it. That hasn’t been the case in this country since the 15th. Century and the progressive introduction of chimneys. The only down side is the fire hazard aspect, you have to have a properly built and maintained chimney which needs to be swept at least annually before you start to use the fireplace, or alternatively use electric heating which negates virtually all the hazard from fire.

Presumably the above poster talking about chimneys in thatched houses is not talking about kayabuki houses in Japan. The story and my comment are about thatching in Japan with Japanese materials in the Japanese climate.

Thatch does have other benefits. it is silent when it rains, for example. Metal roofs can be very noisy. One aspect few people will think about is that thatched roofs have to be very steep, 45 degrees or more. This means more material is needed to cover the same floor area and a large and extremely dark loft space is created below the roof. For the same height of building, a low angle roof would give you an extra storey of rooms with daylight and ventilation. In other words, you can halve the footprint of the house (and cost of land if you prefer) but still get the same floorspace. Its much easier to heat a small two-storey house than a big single-storey one.

Japan does have other very attractive roof materials, copper on temples and castles and kawara tiles on houses, so thatch is not the only choice.

In one sense, thatch is indeed environmentally friendly. Spiders absolutely love it.

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