Long Straw Thatch

Long straw thatch is thatch made from cereal straw that has been threshed (historically by flail) without being combed, so the stems are mixed, bruised and laid with both ears and butts visible on the surface. It was once the most widespread thatch across the corn-growing regions of England from Dorset northward and is now most closely associated with East Anglia.

Preparation

Straw from tall, hollow-stemmed winter wheat is cut with a binder while the nodes are still green and stooked in the field for two to three weeks. The thatcher dampens the straw, shakes it onto a bed and draws out double handfuls, which are straightened into bundles called yealms, typically 18-24 in (46-61 cm) wide and 4-5 in (10-13 cm) deep. Straw should average at least 30 in (76 cm) long. Because modern short-stemmed wheats are unsuitable, growers maintain old varieties such as Maris Widgeon and Maris Huntsman; rye and triticale are also used.

Application

Yealms are laid onto a base coat and fixed with split hazel spars. The finished roof is raked rather than trimmed, giving a soft, "poured-on" appearance in which the long straws can be seen. Distinguishing features are external hazel rods (liggers) along the eaves and gables, and usually wire netting over the whole roof to keep out birds. For rethatching, new straw is normally fixed into the existing thatch after the old surface has been stripped back to a sound base.

Lifespan

Many long straw roofs have lasted at least 25 years and some up to 50. Ridges need more frequent renewal.

History and supply

Wheat straw was the main thatching material in lowland England from medieval times until the 1950s, when combine harvesters and short-stemmed wheat reduced the supply of suitable straw. Supply remains fragile: after a wet autumn in 2019 and a dry spring in 2020, many growers reported harvests down by roughly 20-80%. Historic England advises against replacing long straw with water reed on listed buildings without clear justification.