Thatching

Thatching is the craft of building a roof with dry vegetation such as straw, water reed, sedge (Cladium mariscus), rushes, heather, or palm branches, layering the vegetation so as to shed water away from the inner roof. Since the bulk of the vegetation stays dry and is densely packed—trapping air—thatching also functions as insulation. It is a very old roofing method and has been used in both tropical and temperate climates. Thatch is still employed by builders in developing countries, usually with low-cost local vegetation. By contrast, in some developed countries it is the choice of some affluent people who desire a rustic look for their home, would like a more ecologically friendly roof, or who have purchased an originally thatched abode. Thatching methods have traditionally been passed down from generation to generation and numerous descriptions of the materials and methods used in Europe over the past three centuries survive in archives and early publications. In some equatorial countries, thatch is the prevalent local material for roofs, and often walls. There are diverse building techniques from the ancient Hawaiian hale shelter made from the local ti leaves (Cordyline fruticosa), lauhala (Pandanus tectorius) or pili grass (Heteropogon contortus). Palm leaves are also often used. For example, in Na Bure, Fiji, thatchers combine fan palm leaf roofs with layered reed walls. Feathered palm leaf roofs are used in Dominica. Alang-alang (Imperata cylindrica) thatched roofs are used in Hawaii and Bali. In Southeast Asia, mangrove nipa palm leaves are used as thatched roof material known as attap dwelling. In Bali, Indonesia, the black fibres of the sugar palm, called ijuk, is also used as thatching material, usually in temple roofs and meru towers. Sugar cane leaf roofs are used in Kikuyu tribal homes in Kenya. Wild vegetation such as water reed (Phragmites australis), bulrush/cat tail (Typha spp.), broom (Cytisus scoparius), heather (Calluna vulgaris), and rushes (Juncus spp.