Thatch Timbers & Features

This page takes a quick look at the parts, which can make up a thatched roof. The first diagram shows the various timbers in a typical roof. As these are also found in tiled and slated roofs, only a basic picture is shown. In fact a great deal has been researched and written about roof timbers, especially old ones; which need not be repeated here. As this site is concerned more with what covers the timbers….

Basically, large A frames, traditionally set 16feet (4.8m) apart support a ridge board and one or more horizontal purlins. To these are fixed common rafters, usually set 16inches (400mm) apart. Their bottoms sitting on a wide wall plate. On these lie the battens, with a wider spacing than that used on tile or slate roofs. Around all the wall plates is fixed a facia board; although this timbering detail can vary.
1a 150 dpi

Old timbers… The opposite image depicts the interior of a typical old thatch. This being the top of a full hipped roof; dating from around 1775. All appears to be original and in good condition; with a sawn A frame and common rafters mostly consisting of poles, probably of Ash. These support thin battens of split timber. Here an undercoat of long straw has been tied to the timbers with tarred twine.

Modern building regulations specify much larger timbers; but this roof has already lasted two and a half centuries… Photo: courtesy of Milton Abbas Local History Group.

1b 150 dpi
1c 150 dpi

T hese last two drawings show some of the various ‘features’ found in thatching. Real examples are shown below; starting with an almost ‘featureless’ example of ‘straightwork’….. These features are discussed in greater detail on the Technical pages… As noted in the Home page, some of the names given here are not in universal usage.
As will be seen, thatched roofs occur in an unending variation of these and other features….