Timber Framing - Structure

Structure

Timber framing is the method of creating framed structures of heavy timber jointed together with various joints, but most commonly, originally with lap jointing, and then later pegged mortise and tenon joints. Diagonal bracing is used to prevent "racking", or movement of structural vertical beams or posts.

Originally, German (and other) master carpenters would peg the joints with allowance of approximately an inch (25 mm), enough room for the wood to move as it seasoned, then cut the pegs, and drive the beam home fully into its socket.

To cope with variable sizes and shapes of hewn (by adze or axe) and sawn timbers, two main carpentry methods were employed: scribe carpentry and square rule carpentry.

Scribing or coping was used throughout Europe, especially from the twelfth century to the nineteenth century and subsequently imported to North America where it was common into the early nineteenth century. In a scribe frame, timber sockets are fashioned or "tailor-made" to fit their corresponding timbers; thus each timber piece must be numbered (or "scribed").

Square-rule carpentry was developed in New England in the eighteenth century. It used housed joints in main timbers to allow for interchangeable braces and girts. Today, standardised timber sizing means that timber framing can be incorporated into mass-production methods as per the joinery industry, especially where timber is cut by precision computer numerical control (CNC) machinery.

To finish the walls, the spaces between the timbers (in German called Fächer) were often infilled with wattle and daub, loam, brick, or rubble. Plastered faces on the exterior and interior were often “ceiled” with wainscoting for insulation and warmth.

This juxtaposition of exposed timbered beams and infilled spaces created the distinctive "half-timbered", or occasionally termed, "Tudor", style.