Reading Dave Ewing’s paper on the history of moving buildings, I started thinking about the part lifting buildings plays in our work (it’s a starring role), and the part that screws and other simple machines play in that lifting (co-starring the skid steer).
This year, we repaired a barn on Randall’s Hill in Montville. It was a big lift, and hold. The crew spent late fall and winter under the barn digging footers and preparing the ground for both the lift and the posts that would be installed below the undercarriage. The crew cut 6″ x 7″ cribbing into 4′ lengths and piled them, Lincoln-Log style, into ten boxes. Building cribbing piles is something of an art; the piles need to be perfectly level, and when they are neatly cut, they can be checked for plumb at the corners as they are stacked. We build with the 7″ on edge so that each layer is 7″ high. This allows us to slide other cribbing, laid flat on the 6″, in and out of the stack when it comes to lifting and lowering the steel with hydraulic jacks.
We built a wooden track atop the cribbing piles, and placed rollers along them. Derek Davis, of Davis Dirtworks, inserted 35′, 1000 lb H-Beams under the building, and onto the rollers. The rollers we use come from our clapboard supplier, Steve Jeffery, from the center of the log that is left over from manufacturing radial-sawn clapboards. In the 1890s, they also used wooden rollers to move the barn, but instead of a skid steer, they used steer.
So, we slowly rolled the H-Beams into place, and then Derek threaded four 25′ I-Beams under the building (called the “needles.”) The entire grid was leveled across the cribbing piles and then raised to the underside of the first floor framing. We lifted sequentially, using hydraulic jacks set onto cribbing that crossed the “ladder rungs” of the cribbing piles. Considering that the throw of the jack was less than 7 inches, I was surprised that we finished lifting the grid the same afternoon that the beams were installed.
The beams were used to stabilize the building while the cinder block foundation was demolished and replaced with proper footers, frost wall, and timber posts that were tenoned to the sills above. Drainage was installed around the exterior to manage the water that formerly ran through the basement and contributed to undercarriage decay.
One of our main tasks was leveling the posts. Over time, the sills and summer beams had sagged and spread to such a degree that the posts were all over the place. We determined a reference post at the beginning of the project, in the front corner adjacent to the connector ell. At each of the other 23 posts, we used both a water level and laser level to determine how far from level the top of each post was from the top of the reference post. One of the drive posts was more than 5 inches out of level; most of the rest ranged between 2 and 4 inches.
When we were finished repairing the foundation, the steel beams were removed as they’d been inserted. It took an afternoon to lower the beams, using hydraulic jacks, cribbing pile rung by cribbing pile rung, and removed just as gracefully by Derek in the skid steer.
Elsewhere on the project, both during and after the insertion of steel, we repaired posts using a more typical method of lifting and holding, with brackets, screw jacks and jack posts. I will describe multiple approaches to post repair in an upcoming blog post, and more about Randall’s Hill over a series to be published this month. The barn was part of a much larger project to repair the house and barn, and renovate the connecting ell with a clean, modern kitchen. The completion of a project that combined honest, best-practice preservation and the installation of a high-modern contemporary kitchen required a clear vision from the clients and a lot of stamina. I look forward to describing our process in future posts.