More on Japanese Roofing
Aside from a childhood obsession with Legos, I’ve never really been huge into architecture and building, yet something about Japanese style roofing has always caught my eye. I did another post on roofs in Kyoto and one on clay that showed a bit about how roofs are put together in Okinawa and Japan, but a recent trip to the Shikina Royal Gardens gave me the opportunity to learn more about how Okinawan roofs were made while at the Udun Palace.
The first part of any roof is a frame, and like most roofs I’ve seen, the Okinawan roofs use simple wood, similar to 2×4 to create a rigid grid. On top of that is where things start to very by time and location. In the Shikina Gardens, I found one roof with a layer of thin sticks, above the frame You might wonder at this, but the sticks are likely far cheaper than finely cut boards. In order to cover a roof in boards, you would need planing saws and nails. Japan is often very humid, so nails were never a good option for building. Instead, most Japanese architecture relied on interlocking joints that also made for easy rebuilding after natural disasters. Japanese saws are also not well suited for horizontal cutting, making it far easier to cut large rough wood for the frame. Since the sticks would do little to protect against rain, above that was placed red clay tiles joined with a kind of plaster.
How to Make Okinawan Roof Tiles
Inside Shikina Garden’s Kago House was a selection of original tiles as well as a drawing of the process used to create them. The main tiles use were simply 1/4 of a topless cone of clay. The end and corner pieces were smaller but more ornate. The quarter pieces were alternated up and down, and interlocked to create a water-proof barrier and the distinctive Okinawan style still seen today. Where the curving ends met, the decorative corner pieces were installed to cap the gaps.
This drawing shows the various tools used in the creation of the roof tiles on the left. The right shows the beginning of the process, including the creating of clay and the rolling of clay on a rock guide.
This drawing shows the creation of the smaller, decorative, end and corner pieces. These did not taper and were about 30cm long by 15cm wide. They were full halves rather than quarters.
Finally, this shows the creation of the larger tiles. The clay from the first image is wrapped around a form and sealed. When it dries, the inner mold is removed and the cone is broken in half, then quarters. The final dimensions were about 24cm wide tapering to 18 cm along the 24cm length.
These heavy clay tiles, combined with generally low sturdy construction of older Okinawan homes helped combat turbulent weather such as typhoons. Sometimes, bags of small rocks were also placed on the roofs to help keep the tiles in place during extreme weather.