GASSHO-STYLE HOUSES = THE CULTURE OF THE VILLAGE PEOPLE
Let's learn more concretely about the characteristics and structure of the Gassho-style houses.
At first glance, it appears as if all three villages, Suganuma, Ainokura and Ogimachi, which are registered with The World Heritage are the same. However, all of the Gassho-style houses of these villages are different. The Gassho-style houses are based on their own building structures according to their regions characteristics.
First, the slope of the roofs of the Gassho-style houses in Suganuma and Ainokura Village are a bit steeper in comparison with the Gassho-style houses in Ogimachi Village. This is because the snowfall in Suganuma and Ainokura Village is heavier than Ogimachi Village. It is believed that the snow falls much easier from the roofs of Suganuma and Ainokura Gassho-style houses than Ainokura.
One of the characteristics of the Gassho-style houses in Gokayama is that the roof gable is rounded at the end. This is called "Hafu".
Furthermore, the entrance of the Gassho-style houses in Suganuma can be seen from both sides of the roof.As for the Gassho-style houses in the other villages, the entrance can be seen on only one side of the roof.
Another characteristic of the Gassho-style houses are that the structure and uses are different between the first floor and the attic. The attic is two stories high. The bottom floor of the attic is called "AMA" and the top floor of the attic is called "SORA-AMA".
Generally, Japanese style houses contain a pillar in the attic, which restricts the use of the attic. However, there is no need for a pillar in the attic of the Gassho-style houses. The first floor is constructed first, the attic next. Also, there is no stairwell in the roof of the attic. These are the major characteristics of the Gassho-style houses which cannot be seen in any other area in Japan.
The first floor of the Gassho-style houses must be constructed by carpenters, but the assembly of the roof structure can be built by the village people. The village people constructed the roof by "YUI", which is a traditional cooperation system.This system makes it easy for the roof to be built. Thick A-frame crossbeams support the Gassho-style roofs. The economic conditions of Suganuma Village were poor, thus the need for the village people to work together and help each other with the construction of the Gassho-style houses.
A tip is shaved thinly, and the lumber GASSHO-ZAI which makes the roof of the Gassho-style houses is inserted in the holes on both ends of the material of the triangular base. This is called the "pin structure". It transmits the roof and the weight of the snow to the first floor efficiently, and stabilizes the house.
The name of the thick crossbeams that support the roof is called "CHONNA-BARI". The structure of the roof is outstanding and can withstand the weight of the heavy winter snowfall.
To increase the strength of the house against earthquakes and strong winds, lumber is placed between the crossbeams. This lumber is called "SUJIKAI". The wooden pillars that support the roof are called "HANEGAI" or "KOHAGAI".
The Gassho-style houses are flexible to cope against extreme weather conditions. The roofs of the Gassho-style houses may not be level. This is because the roof can be diverted on purpose to withstand the weight of the snow.
Construction of the Thatched Roof
The most distinctive part of the Gassho-style house is the thatched roof. The construction of the thatched roof requires many people. The roof is constructed by YUI. YUI refers to the neighboring people who volunteer their time to help construct the roofs.
First, the straw from crops is used to thatch the roof. In Suganuma, the material used to thatch the roof is acquired in the autumn. It is dried and used as a snow fence around the Gassho-style house. Re-thatching of the roof is done either in the spring or autumn.
The people of the village gather early in the morning and work all day long. First, scaffolding is setup and the old roof is torn off. Before the new roof is constructed, the straw from the old thatched roof is divided into good and bad straw. The good straw is reused to thatch the new roof. The old straw whose quality is still good is mixed with new straw and is used at the top of the roof.
Each side of the roof is divided into three. The re-thatching of the roof is done in three stages. The re-thatching of the roof is constructed from the bottom to the top of the roof. The bundle of thatched straw is joined at the end, beside the roof.This process is called "HAFU-JIRI". The angle of thatched straw is linked to the eaves by HAFU-JIRI.Only skillful craftsmen can make HAFU.
The eaves of the roof are made along HAFU-JIRI. This part is called "OJIRI". The thickness of the roof is decided by OJIRI.That part of the surface of the roof is covered with thatched straw.
If the borderline between the old and new thatched roof isn't covered, the HAFU may leak from the rain and snow.
Lastly, short thatched straw is used to cover the ridge, and long thatched straw is bent and wrapped over the ridge.
This is a time consuming process and must be repeated five more times. Even if it rains, it must be finished in one day.If the roof is not completed, it will become putrid or rotten.
When the work is completed, all the workers eat dinner together and heal from the fatigue of a long days work. With the existence of YUI, the thatched roof can be completed in one day.