| |
Timber framing is a method of erecting structures with large wooden members
through the use of pegged mortise and tenon joinery. This technique of
construction is as ancient as our dependence on wood as a building material.
Evidence of joined timber frames in western cultures date back to 6220
BCE in Macedonia.
By the third century CE, the form of timber framing that is familiar to
most had already evolved into the common building method used by peasants
in northern Europe. Timber framed Stave Churches in Scandinavia built
in the 8th century are still standing to this day. The 10th century saw
an explosion of complex timber framed roofs in cathedrals across Europe.
These remain some of the world's most remarkable architectural and engineering
feats.
In England, timber framing reached its peak around the 14th century with
varying forms and styles, most notably the cruck frame and the Wealden
House style. France and Germany also have a rich tradition that continues
to this day. Colonists from these (and other) countries brought their
tradition and style to the New World, examples of which can still be found
throughout North America. |
Joinery detail.
Jack Sobon's Barn in Windsor, Mass.
|
| |
In Japan, timber framing became a predominant building
method due to the archipelago's rich resources and history of fierce
wind, rain and earthquakes. Timber frames, with its fibrous timbers
and hinge-like joints, bend with forces unlike stone or brick which
would crack and break. The 6th century CE saw the completion of two
of the world's oldest surviving wooden structures - the Golden Hall
or Kondo (679 CE) and the Pagoda or Goju-no-tu (693 CE) at the Horyu-ji
near Nara.
Timber framing is economical in its use of materials with very little
production of waste. Unlike stick-framed walls, almost any type of wood
may be used (dependent on known physical characteristics of different
woods and engineering principles; i.e. loading) and depending on your
building code, you can harvest the timber right off your own property!
Timber frames generally uses less wood than a stick-framed home and
because there are specific sizes required for the various members, you
can pick and choose trees based on their size and characteristics. This
makes for a more efficient use of the material. For example, if
you needed an 8"x8" timber, you would need to harvest a 10"
diameter tree.
Timber frames are a great building system to use newer (and older) building
envelope systems to make a home more energy efficient. The popular use
of SIPS [structurally insulated panels] make for a very tight home.
SIPS are plywood sandwiches with polystyrene as the 'meat', which can
be used for both walls and roofs. The SIPS mount right onto the frame
and has a R-value of R-25, whereas a conventional stud frame with batt
insulation rates at about R-13.
Timber frames and straw bales and/or light straw/clay systems compliment
each other very well. The two systems form an extremely thermally efficient
building that can last generations. The straw bales or light straw/clay
envelop the timber frame which protects the frame from the elements.
A timber frame home with a straw-based exterior with an earthern plaster
(or lime) can easily last 500 years with proper upkeep and good, initial
design and detailing. And if one so chooses, one can de-construct the
frame and reuse the members and use the walls (straw and clay) as mulch!
Other than the historical significance of the timber frame, the appeal
of this building form is on the human level. Timber framing is a dialogue,
at times a chorus, between people and materials. Luckily, timber framing
has yet to be mechanized in any substantial way. There are modern CNC
machines (computerized numeric control) that can cut large members but
they have yet to mass produce frames to significantly alter the craft.
It is still very much about craftsmanship and the personal - both for
the framer working the wood, her hands and her mind; and also for the
owner who feels a deep connection to her home whose beauty lies in its
form as function.
|