To maintain them, traditional methods and materials are employed, varying from region to region. There's even a cultural association dedicated to thatching, which works to maintaining traditional houses with thatched roofs. Photographed here is a thatched roof tea house at the Hōgon-in temple in Arashiyama, Kyoto.
EXIF info:
Nikon Df
Lens: VR 28-300mm F/3.5-5.6G
Focal Length: 24mm
Aperture: F/2.8
Shutter Speed: 1/60s
ISO Sensitivity: ISO 4000