Thatching Terms

On this page we have detailed the most well-known and commonly used Thatching Terms and Definitions.

Apron: Single sided section of ridge to protect thatch under chimney or window.
Arris Rail: See: Tilting Fillet.
Back Filling: Laid above battens and under main thatch, used to adjust the tilt of reed or straw.
Barge Board: Solid board used as an alternative to turned gable or cut gable end.
Battens: Timber battens are laid horizontality at 300mm centres. 1”x2” is suitable for screw fixings larger will be required for crooks.
Biddle: A working platform that is hooked into the thatch.
Binder: Reaper for cutting standing corn as part of the harvesting process.
Bottle: Tied Yelm of straw for setting eaves and gables.
Box Gutter: Leaded gutter & flashing formed behind chimney to maintain weather proofing.
Brow: The course after the eaves course, which adds to set the pitch of the roof.
Butt: The thicker end of a bundle of reed or straw.
Butting: Arranging the ends of the reed by dropping bundles onto a board or using a spot board.
Cheek: The side of window.
Coat: Layer of entire thatch or sometimes used to describe a new layer over an existing roof.
Combed Wheat Reed: Straw which has had the corn leaf and weed removed.
Course: Layer of reed or straw laid across the roof i.e. horizontal.
Crook: A thatching nail used to fix sway to rafter.
Dressing: Pushing reed into final position by striking with a drift or Legget.
Drift: See: Legget.
Dutchman: Type of Legget originating from the Netherlands.
Eave: The first course of thatch.
Eyebrow: A window or eyelet, high in the wall requiring a curve of the thatched eave over it to keep it functional.
Face: The surface of the main roof.
Gable End: The overhang of thatch at a gable of the roof.
Gadd: Cut length of hazel between 1″ & 3″ in diameter, before being split into Spars or Liggers.
Knuckle: Handful of straw, bent double.
Legget: A wooden tool, used to drive combed wheat & water reed into position.
Ligger: Split Hazel or Willow rods used to form a decorative pattern on ridges and around the edge of long straw roofs.
Long Straw: Straw thrashed but not combed.
Netting: A ¾” galvanised wire or ¾” polythene net used to protect thatch from bird damage.
Needle: Used to stitch on the thatch around the sway & rafters/battens.
Pinnacle: Top most bundle of ridging material used to shed water back onto the ridge.
Pitch: The angle of the roof, 45° is the accepted minimum for the roof pitch. 50° considered better to aid the follow of water.
Ridge: Covering of supple straw or sedge grass, laid along apex of roof to bind and protect the main thatch. Types include wrap-over, butt up, flush, straight cut and patterned.
Ridge Roll: Continuous parallel bundle of thatch used to build up ridge.
Rod: Hazel or withy, used to hold down thatch on the surface, galvanized rod can also be used.
Rye Straw: Type of soft straw used for thatching, mainly used for ridging a water reed roof.
Screw Fixings: A screw attached to a stainless steel wire is fixed into the battens and the wire fastened to the sway.
Sedge: Marsh Grass (Cladius Mariscus) used for ridging.
Set: See: Tilt Fillet.
Sheaf: Bundle of un-thrashed straw – 8 sheaves make a stook & 16 make a stock.
Spar: A split length of hazel or withy, pointed and twisted to form a staple, used to secure new thatch to an existing roof.
Spot Board: Board for `butting up` of reed bundles.
Stalch: A strip of thatch worked from eave to ridge.
Standing Crop: The thatching materials whilst growing.
Stool: Clump of growing hazel.
Straw: All types of straw which may be used to thatch.
Sway: Split or round rods made of steel, hazel or willow are used with spars, iron crooks or screw fixings to secure thatch over coats or to rafters horizontally in parallel with the line of the eaves.
Thatcher’s Square: Traditional measurement for the area of a thatched roof (10ft x 10ft).
Thrashing: Methods of removing grain from straw manually or mainly mechanically now in a thrashing drum.
Tilting Fillet: A `V` section of timber is used at the eave and gable to set the roof off at the right angle to ensure correct tension is started on the roof.
Wadd: A small bundle of material to continue the action of the tilting fillet.
Wand: Length of un-split willow or hazel, less than 1″ in dia.
Water Reed: (Phragmites Communis) Obtained traditionally from East Anglia now additionally from other countries around the world.
Withy: Willow used for rods sways & spars – it is said to be less prone to woodworm
Yelm: A prepared drawn arm full of Long straw or Sedge which is used like a thick roof tile