For me, one of the most intriguing things about the Yale triscuit-studwall system is its size. Here at Trinity University, we generally support platforms on 4′ centers regardless of their size, so the concept of lightweight, thin-profile 4×4 stock platform units made a great deal of sense. I enthusiastically set out to make some triscuits for my theater, but finding lumber difficult to locate in my area, I decided to use thin-wall tube steel for the frames. That choice prompted the development of the triscuit described here.

FIGURE 1: THE TEXAS TRISCUIT

The Texas triscuit has a welded frame consisting of four lengths of 1½″ × 1″ and two lengths of 16-gauge 1½″-square tube steel. Like the original, this triscuit is capable of carrying at least 50 psf, is fastened to its studwall at only four points, and can be used as a sub-floor under any finish layer of decking. It is not a double-sided stressed-skin like the original, however, and since it is skinned with ⅝″ plywood on just one side, it has a 2⅛″ profile and weighs only 56 pounds.

CONSTRUCTION NOTES

The use of steel tubing retains the strength advantages of the wood-framed triscuit and simplifies the construction process somewhat. Drilling the four hold-down holes in the 1½″-square tube steel end caps is the first step, but the size of the holes depends on the choice of fastener to be used. Since I use 3″ drywall screws, I drill ¼″ holes. Those who prefer to use lag screws should drill ⅜″ holes instead, as Figure 2 illustrates. In either case, the holes should be drilled on the centerline of the 1½″-square tube, ⅜″ from the ends as shown in Figure 1. After drilling the four holes, lay out the four cross members between the two end caps, square and weld the frame, and grind the top and bottom welds flush. Set the plywood on the frame with the grain parallel to the cross members, and attach the lid to the frame with self-tapping screws 6″ apart. Turn the assembly over, and drill the four hold-down holes through the lid. Countersink or counterbore the plywood as necessary to accommodate your choice of studwall fastening hardware. See the notes in Figure 2.

CUT LIST

INSTALLATION NOTES

Like the originals, steel-framed triscuits are to be laid out with the four cross members running perpendicular to the studwalls so that four rather than two framing members cany the load. An ⅛″ gap left between the triscuits prevents them from squeaking as they flex under floor traffic.

FIGURE 2: FIGURE 2: HOLD-DOWN FASTENER OPTIONS

FINAL OBSERVATIONS

The steel-framed Texas triscuit is a useful option for stoc platforms. Their size and shape make them easy to handle and store. The welded frame should last forever and the plywood deck can be replaced as needed. At a cost of less than $30 apiece, they offer an efficient and effective alternative to traditional plafforming methods.