Building a deck and jig for the market trusses
Last week we finished up some remaining odd jobs and are now in full-fabrication mode for the farmers market structure. Because we have some legal limitations working with minors on a construction site (they are not allowed to use power tools if under age 18), we are doing as much as we can before the end of the school year to prefabricate components like the roof trusses.
In order to fabricate the trusses, which will delineate the 8 bays and vendor stalls within the market pavilion, we need to build a large jig to produce them consistently each time. The trusses are 24 feet tall and 24 feet deep, with each subsequent truss from the end of the structure losing a bit of depth, giving the front facade an angle. The jig we are building in the shop is 24×24 feet to accommodate the largest of these trusses, and is made up of nine separate 8×8-foot modules, bolted together.
Students are fabricating them based on a framework of 2×4′s and OSB with vertical and horizontal bracing. Once perfectly leveled and built with all nine modules assembled, the OSB top will be the deck upon which we build each of the roof trusses. Jig pieces and guides will be screwed to the deck to ensure consistent fabrication each time. Cameron does a great job of explaining this process in the video above. Hopefully by the end of the week, the whole deck and jig will be built and we’ll be starting truss construction!