Topic summary
Thatched roof
Extracted from the Wikipedia article Thatching.
Disadvantages
Whether thatch can cope with regular snowfall depends — as with all roofing materials — on the strength of the underlying roof structure and the pitch of the surface. A law passed in 1640 in Massachusetts outlawed the use of thatched roofs in the colony for this reason. Thatch is lighter than most other roofing materials, typically around 34 kg/m (7 lb/sq ft), so the roof supporting it does not need to be so heavily constructed, but if snow accumulates on a lightly constructed thatched roof, it could collapse. A thatched roof is usually pitched between 45 and 55 degrees and under normal circumstances this is sufficient to shed snow and water. In areas of extreme snowfall, such as parts of Japan, the pitch is increased further.