What is a rail in carpentry?
A rail is a horizontal member, usually timber and occasionally aluminium, that connects the upright parts of a construction. The vertical members are called stiles. The Dutch equivalent, “regel”, is a broader word covering horizontal timbers and battens in general.
Where you find rails
- Panel doors. The horizontal frame members are the top rail, middle or lock rail, and bottom rail. The panels sit between stiles and rails.
- Timber framing. Horizontal members between the posts tie the frame together and divide the wall into bays.
- Roof battens. In Dutch usage, the tiling battens that tiles hang on also count as “regels”.
- Battening for cladding. A grid of timber battens forms the substrate for boards, linings or external cladding.
Application in practice
Doors. In traditional panel doors, rails are usually joined to the stiles with mortise and tenon joints or dowels. The bottom rail is normally deeper than the top rail. When repairing an old door, rot is often found in the bottom rail and the foot of the stiles, where water collects.
Roofs. Tiling battens run horizontally across counter battens that follow the roof slope. The counter battens create a space for ventilation and drainage beneath the tiles. Batten gauge depends on the tile, so always take it from the manufacturer’s data rather than guessing.
Walls and façades. The board manufacturer sets the maximum batten centres. Place a batten at every board joint so that each board edge is supported.
Common mistakes
- Mixing up rails and stiles on drawings or cutting lists, which leads to parts cut to the wrong length on site.
- Using untreated or overly wet battens externally.
- Gluing a solid timber panel into the groove of the rails. A solid panel must be free to shrink and swell.
Related terms
- Panel door
- Bottom rail
- Frame stile
- Batten
- Battening
- Timber frame construction
Want to learn more about construction terms? Visit our knowledge base at fredsdiyplans.com.