The Eagle has landed. Our timber frame, having spent a month in the air supported by a pair of bridge trusses, is back on solid footing. The owner, the engineer, and the carpenters all are very relieved.
Whereas assembling the trusses and lifting the timber frame took north of a week, getting it down took only half a day. Clayton avoided a repeat of the Great November Jack Rental Fiasco and bought four bottle jacks of his own. Jacks in hand, we stationed one person at each of the four corners, plus a fifth to check vertical alignment and tighten a come-along if necessary.
We pumped the bottle jacks within half an inch of their highest setting and positioned them inside the cribbing towers below the truss ends. Then, all together, we pumped the jacks a little higher, loading them with the entire weight of the structure.
Each jack has a nifty little dial on the front that releases air pressure. You can control the speed of air release, and therefore the speed at which the jack descends, by how far counterclockwise you turn the dial. (Lefty loosey.) To stay together, we measured the gap between our new floor and the timber frame’s four outer posts. We agreed on the next measurement (i.e. from 7 inches to 6½ inches) and lowered our jacks to that point. We repeated this process until the jacks had fully descended.
The next step was very similar to lifting: we rearranged the cribbing towers and used scrap lumber to support the truss ends at their new elevations. Then we released the jacks, reset them to their highest point, and repositioned them. We iterated until the timber frame landed gently on the floor.
Not done yet. Two of the posts had spread while the timber frame was airborne, so they didn’t land in the right place. Using Timberlok screws to pin the rest of the frame and The Persuader (our resident sledgehammer) to move the posts by force, we got the timber frame squared up like it used to be. Now on to actual construction!
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