Friday, December 26, 2008

"Itabuki" 板葺: Otaki's traditional roofing

In my previous post I wrote briefly about the wood plank roofing that used to be used in Otaki. These days most homes are roofed using sheets of red tin (I still don't know why red). The tile roofing that is common throughout most of Japan is rarely used--the heavy winds and snows of the area are not friendly.

Wooden planks make sense in Otaki because the village is surrounded by forest. From what residents have told me the planks they used in the past came from the Imperial Forests--known as 御料林 go-ryourin. Sawara cypress was the variety of tree most commonly used for planks.

The wooden planks were laid on top of a roof frame in a staggered pattern with planks on top overlapping those below them, ensuring a watertight covering. Wood-smoke from inside the home would then work to treat the underside of the roof, while the upper-side--exposed to rain and snow--tended to rot. The roof would, therefore, be periodically disassembled and the planks rotated so that exposed sections could be cured by the wood-smoke and previously cured sections faced outwards towards the elements. The planks are rotated and used four times: the initial pattern, an oblong rotation, a single flip, and then one more oblong rotation.
Longer pieces of wood, running the length of the roof, were laid perpendicular to the roof planks and then lined with large rocks to hold the whole thing in place. Otaki's traditional roofs, like the house structures themselves, required no nails--no metal--only wood and stone.

There are only a few of these roofs left in Otaki. I first heard about the old construction techniques during a vist from a Tokyo woman in Kiso to learn lacquerware. She was in Otaki searching for examples of old lacquerware that she could show her teacher. After noticing some of the old planks in my friend S-san's home, the woman was shocked to learn that S-san was using the planks as kindling. The woman used a couple of the planks to create lacquerware plates. She was searching for more, and so a neighbor brought over some unused planks.
One could see clearly how the planks had been peeled from their parent tree. Each plank is chopped away from a larger pie-shaped section of tree. Imagine cutting out a slice of cake and then cutting that slice into a series of thinner slices. Put differently, if one had all the planks from a section of tree, its round shape could be reconstructed by standing the planks on end and fitting them into one another. The grain of the tree runs down the length of each plank, with the tree's growth rings marked across the width.

These planks are beautiful in and of themselves, as objects, but I find beauty in their utilitarian value as well--whether as roofing or firewood (though I prefer the former). Otaki's itabuki made life possible for humans living within the environment from which they themselves were procured. In the global economy, this is a value embodied by fewer and fewer "things". For this reason, more than seeing these wonderful structures preserved, I'd like to see the tradition revived.


Ojisanjake said...

I've helped put a couple of cedar shingle roofs on here... even with directly importing from Canada, paying customs, renting abig truck and driving up to Kobe Port to pick up the shingles it was still cheaper than any other roof in Japan save tin. One would think that cedar shingles would be easy and cheap to produce in Japan ne?

Also, check out this roof on the Oki Islands

Alex said...

Great post! Thanks for the additional detail.

Denver roofing contractors said...

the roofing looks beautyfull