One way to build without conventional vertical shores is to use long-span form panels supported by brackets or jacks attached to the bearing walls or columns of the building itself. Special hardware of several types is available, some supported by bolts through the columns or walls and some by friction collars. Column-mounted shoring is a term used to describe some of these devices. Usually they have a jack to adjust elevation, and they may have rollers to aid in sliding out the form panels for lifting to the deck above.
One of several systems for forming without vertical shoring has support brackets with up-and-down adjustment bolted to concrete columns. These brackets carry steel beams on which telescoping headers are supported. Heavy plywood panels are fastened by screws to the headers. Another system has open-web joints hinged to I-beams so that the form structure can be folded for shipment. At the jobsite, a crane supports the form for unloading and unfolding to full width. The framework is squared and the remaining bolts are attached and tightened. Wood stringers are then attached to the headers by nails or clips. Plywood decking is applied checkerboard fashion to eliminate any continuous joints across length or width of form.
Friction collars which can be attached to square, round, or rectangular columns carry brackets to support column-mounted shoring. Load capacities of 50,000 pounds per side are readily available, and some will support 75,000 pounds on each bracket. These collars solved a problem in building Union Carbide's headquarters in Connecticut. An irregular, rough, sloping site, frozen or muddy ground, and the need to have the support system in place until the third floor was concreted virtually precluded the use of conventional shoring to support the first floors. The collars, fastened to round columns, provided shore-free support for framework of steel beams and stringers on which precast concrete planks were laid as forms for the cast-in-place slab.