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Timber framing is the method of creating framed structures of heavy timber jointed together with pegged mortise and tenon joints (lengthening scarf joints and lap joints are also used). Diagonal bracing is used to prevent racking of the structure.
 Historically the timbers would have been hewn square using a felling axe and finish surfaced with a broad axe. If required, smaller timbers were ripsawn from the hewn baulks using pitsaws or frame saws. Today it is more common for timbers to be bandsawn and the timbers may sometimes be machine planed on all four sides.
To deal with the variable sizes and shapes of hewn and sawn timbers the two main historical layout methods used were: scribe carpentry and square rule carpentry. Scribing was used throughout Europe, especially from the 12th to the 19th centuries, and was brought to North America where it was common into the early 19th century. In a scribe frame every timber will only fit in one place so that every timber has to be numbered. Square rule carpentry developed in New England in the 18th century and features housed joints in main timbers to allow for interchangeable braces and girts. Today regularized timber can mean that timber framing is treated as joinery especially when cut by large CNC machines.
 To finish the walls, the spaces between the timbers were often infilled with wattle-and-daub, brick or rubble, with plastered faces on the exterior and interior which were often “ceiled” with wainscoting for insulation and warmth. This method of infilling the spaces created the half-timbered style, with the timbers of the frame being visible both inside and outside the building.
In the United States and Canada the art of timber frame construction has been revived since the 1970s, and is now experiencing a thriving renaissance of the ancient skills. This is largely due to such practitioners as Steve Chappell, Jack Sobon and Tedd Benson who studied old plans and techniques and revived the technique that had been long neglected.
Timber framed structures differ from conventional wood framed buildings in several ways. Timber framing uses fewer, larger wooden members, commonly using timbers with dimensions in the range of 15 to 30 cm (6" to 12") as opposed to common wood framing which uses many more timbers with their dimensions usually in the 5 to 25 cm (2" to 10") range. The methods of fastening the frame members also differ, in conventional framing the members are joined using nails or other mechanical fasteners while timber framing uses mortise and tenon or more complex joints which are usually fastened using only wooden pegs.
Recently it has become common to surround the timber structure entirely in manufactured panels, such as SIPs (Structural Insulating Panels). This method of enclosure means that the timbers can only be seen from inside the building, but has the benefits of being less complex to build and offering more efficient heat insulation. Structural Insulated Panels are a sandwich construction of two rigid composite materials usually wood based like OSB or plywood with a foamed insulating material in between either by gluing billets as in EPS (Expanded Polystyrene) or foamed and formed in place with polyurethane. The advantage of this for timber framing in the modern world is less of a dependency on bracing and auxiliary members like minor joists and rafters as the panels can span a considerable distance and greatly increase the stiffness of the timber frame itself.
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