User:Vermont.timber/Bent (structural)

Here is a bent in a finished timber frame home.

A stack of bents ready to be "flown" into place by a crane

A worker directs the crane operator with hand signals as a bent is flown into place

A bent is a structural entity composed of several timbers that defines the cross-section of a timber frame. Bents are the building blocks which define the overall shape and character of a the building. They do not have any sort of pre-defined configuration in the way that a Pratt truss does. Rather, bents are simply cross-sectional templates of secondary timbers (i.e. rafters, joists, etc.) which repeat on parallel planes along the length of the frame.

Construction

Bents are generally pre-assembled, either at the timber framing company's shop or at the construction site. After the basic post and beam structure of the frame has been set in place, the bents are then lifted and simply dropped into place one by one by the crane. Next, the workers bring in additional members, purlins, which tie them together and give the frame a more rigid structure. This process is very safe and efficient as it allows a crew to assemble a large portion of the frame without ever stepping off the ground. This in turn, minimizes the amount of time that the crew must spend several stories in the air clambering along beams not much wider than their own feet.

References

• Benson, Ted (September 1, 1981). Building the Timber Frame House: The Revival of a Forgotten Art. Fireside.

External Links

• Glossary Useful terms in the timber framing trade.
• Blog Entry Some good pictures and a short narrative about raising bents.

Category:Structural engineering