Raising a Traditional Timber Frame

A traditional timber frame uses a bent system--in part, specifically to facilitate raising the frame. The bent assembly represents a cross section of the structure, including posts, tie beam, and rafters. The bents are trial assembled in the shop, to ensure an exact fit. Then they are taken apart, coded, and stacked to await shipment.

At the time of the raising, the timbers are first assembled on the ground. The bent that will go up last is assembled first, followed by the next in order of placement, with the first bent to be raised on the top of the pile. The crane lifts the first bent up and places it on the floor deck. It is braced to hold it steady while the connecting girts are fitted into the bent. They too are braced. The next bent is flown in by the crane and connected up with the girts. Once the two bents are tied together by the connecting girts, we have a more stable structure to work on.

After the bents are secured with connecting girts, the loft floor joists are flown in and installed in the loft area. Finally, the ridge beam and roof purlins are flown in and dropped into their housings on the rafters. The area defined by two bents and these horizontal members (connecting girts, purlins, and joists) is called a bay.

We find that it generally takes the Goshen crew approximately two days to assemble and raise a 3- to 4-bent frame, such as standard frames Blackberry Cove and Walnut Creek. A larger frame, with side sheds (such as Sugar Fork) may take up to three days. The conditions of the site have a bearing, of course, since it is a very different proposition to raise a frame on a steep slope which limits crane access compared to raising a frame on level ground.