What is winding (twist) in timber?
A board or door that is “in wind” (Dutch: scheluw) is twisted out of plane: its four corners no longer lie in one flat surface. Lay such a door flat on the floor and it rocks on two diagonally opposite corners. In Dutch building terminology, the same word describes anything that is irregularly out of plane.
Winding usually results from moisture or drying. Timber does not shrink and swell equally in every direction. If one side of a board gets wetter or drier than the other, or if the grain runs unfavourably, the wood twists. That is how twisted doors, shutters and boards come about.
In Dutch usage, the term also covers deliberate out-of-plane shapes:
- A “scheluwe” staircase: a stair whose treads are not parallel because it turns at the bottom or top, using winders.
- A twisted roof: a roof whose ridge and eaves do not lie in the same flat plane, for example a roof spanning between two unequal gables (a hyperbolic paraboloid surface).
Application
For DIYers, winding mostly matters with timber. Tips:
- Spot it: place two straight battens (winding sticks) across both ends of a board and sight along them from the side. If the battens are not parallel, the board is in wind.
- Doors: a slightly twisted door will not sit tight against the stop at one corner. An extra (third) hinge or adjusting the strike plate often helps. Badly twisted doors can rarely be straightened.
- Prevent it: let timber acclimatise in the room where it will be used and seal it on all faces, including the top and bottom edges of doors. An unsealed bottom edge absorbs moisture and is a common cause of warping.
- Choose stable timber: quarter-sawn timber and glulam are more dimensionally stable than flat-sawn solid wood.
Related Terms
- Quarter-sawn timber
- Flat-sawn wood
- Glulam
- Staircase
- Hypar shell
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