Timber framing (Fachwerk), or Half-timbering, is the method of creating framed structures of heavy timber jointed together with pegged mortise and tenon joints.
It is not a term she uses generally for all timber-framed buildings, for elsewhere she writes:
By 1842, the term had found its way into The Encyclopedia of Architecture by Joseph Gwilt (1784-1863).
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.
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 century to the 19th century, 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 (computer numerical control) 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.
A jetty is an upper floor that depends on a cantilever system in which a horizontal beam, the jetty bressummer, on which the wall above rests, projects outward beyond the floor below.
When jettying, horizontal elements can include:
It is in the United States and Canada, however, that 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 mortice 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.
Alternative ways include the use of straw bale construction. The straw bales are stacked for the walls with various finishes applied to the interior and exterior such as stucco and plaster. This appeals to the traditionalist and the environmentalist as this is using "found" materials to build.
Half-timbered construction in the Northern European vernacular building style is characteristic of medieval and early modern Denmark, England, Germany and parts of France, in localities where timber was in good supply and building stone and the skills to work it were in short supply. In half-timbered construction timbers that were riven in half provided the complete skeletal framing of the building.
Some Roman carpentry preserved in anoxic layers of clay at Romano-British villa sites demonstrate that sophisticated Roman carpentry had all the necessary techniques for this construction. The earliest surviving (French) half-timbered buildings date from the 12th century.
Molded plaster ornamentation, pargetting further enriched some English Tudor houses. Half-timbering is characteristic of English vernacular architecture in East Anglia, Warwickshire , Worcestershire, Herefordshire , Shropshire , and Cheshire, where one of the most elaborate surviving English examples of half-timbered construction is Little Moreton Hall In South Yorkshire, the oldest timber house in Sheffield, the "Bishops' House" c.1500, shows traditional half-timbered construction.
Half-timbered construction went with colonists to North America in the early 17th century but was soon left behind in New England and the mid-Atlantic colonies for clapboard facings (another tradition of East Anglia).
The German Framework Road (Deutsche Fachwerkstraße) is a traveling route that links cities with picturesque half-timbered buildings. It is more than 2000km long and stretches across the states of Lower Saxony, Saxony-Anhalt, Hesse, Thuringia, Bavaria and Baden-Württemberg.
When half-timbering regained popularity in Britain after 1860 in the various revival styles, such as the Queen Anne style houses by Richard Norman Shaw and others, it was often used to evoke a "Tudor" atmosphere (see Tudorbethan), though in Tudor times half-timbering had begun to look rustic and was increasingly limited to villages houses (illustration, above left). In 1912, Allen W. Jackson published The Half-Timber House: Its Origin, Design, Modern Plan, and Construction, and rambling half-timbered beach houses appeared on dune-front properties in Rhode Island or under palm-lined drives of Beverly Hills. During the 1920s increasingly minimal gestures towards some half-timbering in commercial speculative house-building saw the fashion peter out.
In the revival styles, such as Tudorbethan (Mock Tudor), the half-timbered appearance is superimposed on the brickwork or other material as an outside decorative façade rather than forming the main frame that supports the structure.
The timber frame structure goes up quickly in its modern incarnation. While some modern shops still cut the timbers with hand tools and hand guided power tools, modern CNC (computer numerical control) machinery has been readily adapted to the task. This eliminates much of the repetitive labor from the process, but still often requires hand-finishing. The complexity of hip/valley joinery as of yet cannot be duplicated by CNC machinery beyond simple cuts. Additionally, due to the rigid timber requirements of CNC machinery, odd sized, tree trunk, hand hewn, and recycled timbers are usually hand cut even in the machine dominated shops.
One aid in speeding up assembly on site is pre-fitting the frame, usually in bent or wall sections that are laid out on the shop floor. This can assure a correct fit and with pre-drilling for the pegs it speeds the site process. This pre-fitting in the shop is independent of a machine or hand cut system. Valley and Hip timbers usually are not pre-fit but careful layout and checking can catch most errors.
In two to three days an average size timber frame home can be erected and within a week to two weeks after that the shell of the house is ready for drying in, which is to say, ready for windows, mechanical systems, and roofing. The shell in this case would be with Structural Insulated Panels (SIPs).
The timber frame can give the home owner the ability to make a creative statement through the use of design and specialty touches like carvings of favorite quotes and incorporating timbers from heirloom structures, like a barn from a family homestead.