Eight Days of Timber Frame

by John P. Lindtner
for BPR 293, Field Site Lab

For the first week of June, the predominant sound at Jerusalem Mill, Gunpowder Falls State Park in Maryland was that of mallets striking chisels and hand-saws cutting timber. Rhonda Deeg, the director of the Building Preservation and Restoration Program at Harford Community College found Glenn James of Craftwright, Inc. to teach the almost forgotten trade of timber framing. Half of the class consisted of students of Harford Community College while the other half was made up of individuals who had heard about the class and also wanted to get some hands-on experience in timber framing. Students’ ages ranged from 21 to 78. Skill levels ranged almost as much as their ages but enthusiasm always remained high.

The goal for the timber frame field site course was to help reconstruct the wheelwright shop that once stood next to the blacksmith shop at Jerusalem Mill. The original wheelwright shop was about 28 x 25 feet. Our reconstruction was designed to be only 16 x 16 feet- a smaller structure to facilitate it being moved if an archaeological dig was to be done at the site in the future. As a class, we learned the basics of timber framing while also learning that timber frame structures were often over-engineered well beyond the today’s construction methods that emphasize building to meet minimum standards. Glenn assured us that our great-grandchildren would be able to visit the site in a century and see what we had built.

On our first day, Glenn James taught us about the history of timber framing that began over two thousand years ago. We then spent an entire afternoon learning how to correctly sharpen the chisels we would be using. Sharp chisels are crucial in the mortise and tenon joinery. The next morning we were shown how to layout each timber and began working in pairs on our assigned section of the frame. For six days we worked on the timbers creating the mortise and tenon joints that would be supporting the structure. The tools we used were identical to what was used a century ago. Framing chisels and mallets were used to create the joinery. A hand drill was used to drill the holes for the pegs that were shaped using a drawknife and shaving horse.

We worked with enthusiasm through all sorts of conditions. One day we huddled together under tents, as it rained, to get our work done. On other days we worked as the mercury hovered around 90 degrees F. We worked in small groups, but as a whole we worked as one big team understanding that everyone’s task had to be honed to a high level of precision to successfully raise the timber frame structure.

On our final day, after lunch, we assembled the individual timbers we worked on for the prior week and together raised the structure. All available hands were required to help raise the structure. There was no turning back once parts of the frame were halfway up in the air. It took only a few hours to raise the frame and drive the pegs in place to secure the joinery. Not a single nail was used in holding the skeleton of the structure together. A few days later, more than half the class returned to add the roof rafters and nail down the floorboards.

It was rewarding to finally see the completed structure after all the sweat, blood, and minimal tears had been shed. It is even more rewarding to know that the wheelwright shop will hopefully spend the next couple of centuries where it once stood.