3 Things Timber Framers
Want to Keep Secret
As a timber framing company we are advocates for the beautiful and durable structures timber framing produces. The following 'secrets' are only small glitches in the big picture. They are weak points often difficult to acknowledge; however, acknowledging them will improve the total package, as straight facts are more beneficial for the planning of your home.
Hidden Costs of Timber Framing vs. Conventional Framing
Comparing costs between timber frame homes and conventionally built homes can be very hard to quantify. This is largely because timber frame homeowners have a high-quality once-in-a-lifetime mentality. They tend to choose high quality over price across the board, which makes the square foot price of timber frame homes substantially higher. The volume of timber alone is a direct added cost because the exterior shell could easily be load bearing (i.e.: typical stick-built house) which uses substantially less lumber. Finishing the beams adds material and labor cost. Timber framing also creates more work for plumbers, electricians, sheet rockers, and painters because they have to modify their system to accommodate the timbers. The extra cost definitely is not wasted.
Timber frame structures last hundreds of years whereas conventionally built homes are designed to last 50 years. Timber framing increases the resale value of your home significantly. Timber frame homes are also energy efficient when combined with SIP (Structural Insulated Panels), which saves on your heating and electricity cost.
Shear Analysis for Timber Frame vs. Regular Frame
Timber frame joinery is an elegant but inefficient way to join timbers. In order to create a solid connection, you must remove a substantial amount of wood from both timbers, which of course reduces the strength of both members. Careful frame analysis must be applied because failure at one joint means failure for a substantial percentage of the frame. Whereas with stick-built, the same load may be spread out over thousands of nails, therefore diversified.
Shear analysis aside, timber framing is far superior to conventional construction because most members are working at 40% or less of their load capacity. This is due to the fact that joinery is usually the decisive factor in beam sizing, not load capacity. Therefore, if careful shear analysis is applied to timber framing (larger knee braces, deeper tenons, and thicker pegs) then the final result truly is stronger than conventional construction.
Difficulty of Complex Roofline Design
Actually, timber framing a complex roof is difficult only when money is an object. Complex rooflines are often extremely expensive, often unattractive. Visualize a 90's style hip roof with complex hips and valleys in proximity to each other. With a vaulted and timber framed ceiling, this roof would look very busy and convoluted from the inside.
This negative aspect doesn't greatly affect timber framers and architects, because typically, timber frame designs adhere to the clean designs of the past. Protrusions or expansions to accommodate additional criteria cannot be added randomly, but must remain true to timber frame values of thoughtful and careful planning.