Preserving historic structures is one of the most rewarding aspects of being a timber framer. We were thrilled to be contacted about rebuilding the Pine Mountain State Park timber frame pavilion in Kentucky. The park opened in 1924 as Kentucky’s first state park. In 1933 the CCC constructed the round log timber framed pavilion atop Kentucky sandstone walls. Our mission was to create a replica of the structure and raise it on the existing walls. To keep the pavilion as true to the original as possible we sourced new white oak logs from Kentucky.
The original Pine Mountain State Park timber frame pavilion - built by the CCC
Based on pictures sent to us by the contractor we initially thought we could keep and reuse much of the original structure. But then we made a site visit……. You could stick your finger into most of the logs and very little was salvageable. Eight short poplar pieces ended up being reused as knee braces. Next up, demolition; disassembling the original roof system, field measuring and surveying. We kept a few token pieces of the original pavilion, the contractor kept a few, and the park kept the rest of the salvageable pieces for repair work on other existing structures.
The original structure was built with 14x18” plates, hewn on two side, primarily oak. The 6-8” round log rafters and truss members were mostly poplar. The engineer stressed that when ordering timbers, we should err on the side of bigger, and so we ultimately used 16x20” plates and 10-12”rafter and truss members. Needless to say, none of the pieces could be moved by hand, which added to the difficulty of this project. The first step in the process was debarking all of the new logs.
Of course, creating a square building with a consistent roof plane with mostly round timber is challenging. When you couple that challenge with a rushed schedule, you’d better come up with some good, repeatable systems for cutting. All the joinery would be cut with chainsaws. We decided to assemble the whole structure in our shop yard as we cut each piece, which allowed us to check our systems and make adjustments as we went along.
The plates came first, which were half-lapped at their joints. Once assembled, we squared the plate system based on the centerlines that were snapped on the top of each timber. These plate centerlines were crucial to the entire process, as they were used to reference the bird’s mouth joinery on the rafters. Similarly, these lines were used to reference the mortises that housed the thrust blocks, which were required at each rafter location. The thrust block idea was new to us.
When the time came for cutting the roof system, we divided our crew into teams. One team cut and assembled the four trusses that served to resist the spreading force imposed by the roof onto the plate system. Another team worked on cutting common rafters. Still another team worked on sorting out hips and jack rafters.
Templates were employed to ensure consistent joinery on both peaks and tails of the rafters, while allowing for speedy production. Trusses were scribed together, laid up over centerlines that were snapped on the concrete shop floor. As a truss was completed, it was moved out of the shop and placed on the structure, making room for another to be scribed. As a set of common rafters was cut, it was assembled on the structure. When all common rafters were cut and assembled, the common rafter team moved into cutting jack rafters, which were well underway. Without each member of the team, this project could not have been completed on time.
One member of our team was dedicated to hardware installation during the entire assembly. The engineering of the project required a through-bolt (in addition to the afore mentioned thrust block) at each rafter to plate connection. This required a twenty-five inch long hole to be drilled through the rafter and the plate, along with countersink holes to recess the hardware. Bolts were also required through the half-laps at the rafter peaks. The jack to hip connections required two RSS screws, several of which broke off in the grip of the white oak as we disassembled the structure.
Most of the assembly done in our yard was done in the rain (and we were the talk of the town). The project had a very tight schedule, and needed to be completed, with roof and all, before the Kentucky Governor’s annual party in the pavilion in late March. So, once we disassembled the structure we loaded up two tractor trailers and our trucks, and headed straight to the state park.
The site lacked any good flat spots to assemble the trusses, and the trucks carrying the timbers could only make it to about 200 yards from the site. The timbers had to be moved one at a time, slung from a forklift, through a narrow path, across a creek and up a hill.
Once we got started on site the crew worked 10 days straight, determined to get it done. They did get to scope out the park, which has a beautiful CCC built lodge, nice cabins, great trails, and a zip line. One night they enjoyed the “Frontier Dinner” at the lodge, complete with bison, elk, and frog legs.
Challenging projects help us learn and grow, improving our skills and teaching us new techniques. Each person who helped on this job contributed in some way, large or small, to its success. Knowledge we have gained from the Timber Framers Guild has helped on this and every project we work on. And now it’s on to the next!