Frame of Reference A simple design and a collaborative process are often hallmarks of a successful timber-framing project imber framing is one of the oldest Designers’ desires for longer spans and Timber frames are manufactured in construction techniques known more complex joinery, coupled with in- a variety of ways. Most shops use some Tto man, but it remains one of the creased engineering review rigor, are driv- combination of power tools (chain mor- least understood in the marketplace. Evoc- ing timber framers to include more steel tise machines, etc.) and hand tools, such ative pictures greet us from magazines and in their projects and to use a multitude of as chisels and mallets, for joint cleanup. coffee-table books, encouraging visions metal fastening systems. The steel can be Some specialized companies work in envi- of grand rooms and entrances for homes, hidden within the frame or it can be vis- ronments that are powered by water wheels churches, office buildings, barns and even ible, or expressed. Most often expressed and use only hand tools, others are slightly enhancements to our landscapes. The steel is seen as an integral part of the over- more automated and there are an increas- problem arises after the vision: how do we all design of the structure. ing number of shops that employ CNC design, build and afford the dream? Many timber framers are also work- (computer numerical control) technology. ing with manufactured timbers, including CNC technology allows computer design Timber Framing Today glued-laminated and PSL (parallel-strand programs to communicate directly with The traditional definition of timber fram- lumber) material. These timbers, manu- large robotic milling machines that then ing – “a frame constructed of heavy tim- factured from thin pieces, or “slices,” of cut the entire frame. Some companies cut bers using mortise and tenon joinery that kiln-dried wood and then adhered under entire frames using CNC technology while is held together with wooden pegs” – is pressure, have high tensile strength and al- others cut repetitive components, leav- expanding as the industry and design aes- low designers to achieve significant spans. ing the unique or more visible pieces to thetics evolve. They can also be quite beautiful. be hand-cut. Even in the fully automated AS PUBLISHED IN PERIOD HOMES MAGAZINE n VOLUME 9, NUMBER 5 n SEPTEMBER 2008 frame shops, there is still a certain amount of hand work involved in cleaning up and finishing the frame, and sometimes in the more specialized compound joinery. A Natural Choice In a timber frame, the structure of the building is exposed inside the building. This is akin to inviting the outdoors inside, bringing the occupants closer to nature while providing almost all of the decora- tion that the home or structure may ever need. The interior spaces created are unen- cumbered by structural walls, allowing for an open floor plan that can be reconfigured to the occupants’ needs and have a tangible feeling that exudes warmth, strength and security. Timber framers work with many species of wood and many work with wood that is local to their community. Each species has its own characteristic look and personality. Newly sawn or green oak is particularly per- sonable when it is introduced to the heated This structure features Douglas fir solid king-post trusses with a glued-laminated bottom chord. The ceiling is Douglas fir tongue-and-groove decking that provides a warm feeling and adds to the structural integrity. environment. A framer once told me that his client complained of gunshots downstairs timber frame, leaving the timbers fully pact upon the project budget. Not that any in the night – it was the oak frame check- exposed. SIPS are manufactured off-site of these things are bad, but they should be ing as it dried in the dry heat of the house. and can be pre-cut for windows and door recognized up front by the design team. Timber framers use a variety of species, in- penetrations, further lessening on-site con- Complexity also brings with it increased cluding hardwoods (beech, birch, chestnut, struction waste and construction time. volumes of wood. Timber orders are mea- elm, oaks, maple, cherry and hickory) and sured in board footage, where a board foot softwoods (cedar, firs, hemlock, larch, pine, Design Basics equals a piece of wood that measures one spruce and tamarack). Simple, uncomplicated design does not in. by one ft. long by one ft. wide. Adding Timber framing is one of the most sus- mean boring. It does mean that keeping the hips, valleys and dormers to the frame in- tainable building methods available, sup- design simple, without complex roof sys- creases the total board footage that is pur- porting good forest management, low- tems, multiple dormers and various appur- chased for the project, and the loss factor carbon-input manufacturing processes and tenances, will help minimize costs while in each piece increases as steep angles are energy efficiency. Timber frames are typi- showcasing the timbers without clutter. cut into the timbers. In the case of dor- cally manufactured off-site and raised in a Timber framing is extremely labor in- mers, the total board footage of the roof matter of days. The prefabricated nature tensive. Even frames that have been cut increases and the pieces that are added to of the frame reduces construction time and on CNC machines often require hand the project are much more complex, adding site waste. Also, the choice of enclosure finishing. Every time the timber framer to materials and labor expense. systems for the frame can make it very en- works with the timber, the cost increases. ergy efficient and airtight. So, if you have a kiln-dried, S4S (smooth Collaborative Design A significant percentage of timber frames four sides) timber that is perfectly straight The collaborative design process is an itera- are enclosed with SIPS (structural insulated and the final design requires the same, the tive one that refines the design as the scope panels) that, when installed, form a blanket framer will work with it about three times: of the project evolves and is crucial to a of insulation around the frame that pro- assessing, laying-out and cutting. Each successful timber frame project. Collab- vides a significant R-value, very little ther- time the design becomes more complex – orative design is a communication inten- mal bridging and an airtight barrier. Much such as when the project utilizes antique sive process that has measurable benefits; like a sandwich, SIPS are constructed of wood that is by nature often out of square these may include, for example, identifying two outer layers of OSB (oriented strand and/or filled with nails, hand-hewn finish- synergies between building size, fenestra- board) that are filled with a thick layer of es, hand-carved embellishments and com- tion and mechanical equipment needs, or foam (polystyrene or polyurethane). The pound joinery – the time spent with the synergies between plantings, building ori- SIPS are applied to the outside of the timber increases. This makes a direct im- entation and water use. It is important to assemble the collab- Bringing this team in early lays a foun- openings and door and frame conflicts. By orative design team early in the process, dation of good communication at the out- identifying pitfalls and opportunities early, preferably at the conceptual design stage, set of the project that flows throughout the client will save money and time on the and charge them with developing complete, the entire construction process. It allows frame that can be rolled into the project as solid plans before starting any construc- for tighter bidding, reduces cost overruns a whole. tion. The team should at least include the from change orders and reduces total con- Pam Hinton is the executive director of client, the architect/designer, the builder, struction time. It also sends a message to the Timber Frame Business Council. “Our the timber framer, the HVAC contrac- the construction team that this is a project goal as an industry is to become more in- tor or consultant, the sustainable and/or that has been well thought out. This of- teractive with architects earlier in the pro- civil engineer (if any) and the landscape ten causes the construction team to take cess,” she says. “Our membership of expe- architect. The plans they develop should greater care in their own work, resulting in rienced timber framers can help architects include architectural, structural and fram- a better project all around. and their clients save money and make ing, mechanical, storm water, electrical and Timber framing is a specialty business the projects more successful. Working as plumbing. and a timber framer should be included in a team, the timber framer can do what it Many times clients avoid MEP draw- the design process for a number of reasons. takes to express the architect’s vision in ings to save costs, with the belief that the Most importantly, the lack of interior wood – a good collaboration will express general contractor and subcontractors walls and the prefabricated nature of the the intent of the design and maximize the will be able to develop the best mechani- frame present unique challenges for rout- potential of the materials used.” cal program. When stick framing a struc- ing mechanical systems, and there is little ture, this approach often results in cost wiggle room for changing the frame once it Cost Analyses overruns. Given the prefabricated nature is fabricated. That is not to say that you are There is no doubt that timber framing of timber framing and the limited inte- “stuck” with the framer for the duration is more expensive than stick framing, but rior walls, this approach quickly results of the project.