Materials used for Thatching
Water reed is a tall wetland plant; the Norfolk broads provide the main supply of English water reed.
Through its rise in popularity in recent times Norfolk reed supplies have not been able to satisfy modern demands and now 90% of water reed in Britain is imported.
Water reed bunches are applied to the roof in horizontal courses and dressed into position presenting the butt ends of the material with a uniform appearance.
Water reed is normally attached directly to the roof timbers, however in the south west it is sometimes spar fixed to an existing base coat. Water reed can be used to form very angular shapes and follow complex roof designs.
Combed Wheat Reed
Combed wheat reed is mostly grown using the same varieties as long straw, the material is harvested using a reaper-binder. Combed wheat is processed and threshed by passing the material through a comber. This removes the leaf and grain producing uncrushed stems which can then be laid onto the roof and dressed into position.
The use of nitrogen fertiliser in the 1960’s and 70’s weakened the straw and its longevity; however since then there has been a huge increase in straw quality. Specialist growers have returned to using older, tall stemmed, varieties in organic conditions. It is applied in a similar way as water reed using a legget, and dressed into position often fixed using hazel spars.
Combed wheat is mostly used in the south west, where the roof shapes are generally more rounded with slacker pitches compared to roofs in East Anglia which are steep and angular.
In most parts of England long straw was historically thought to be the most widely used method of thatching, now placed in eastern and central areas. Its process is similar to combed wheat reed but its application is very different.
Threshed straw is shaken into a layered bed; it is carefully wetted and left to steep. Once the material is pliable it can then be formed into ‘yealms’. Long straw yealms are laid and fixed into place, surface rods are used to secure the eaves and verges.
Good quality long straw is grown especially for the thatching industry. The appearance of a long straw roof looks ‘poured on’ and ‘shaggy’ compared to that of the combed wheat roof which is neat and uniformed.