Straight straps stand out among connector products as their characteristic capacities are determined by calculations rather than testing. Unlike joist hangers, hurricane ties, or holdowns, which encounter various forces like shear, prying, and withdrawal on fasteners, straight straps, devoid of these complexities, allow us to compute steel tension and fastener capacity per code. Nonetheless, at Simpson Strong-Tie, we conduct numerous tests on our straps due to our dedication to rigorous testing. Occasionally, we receive inquiries about deflection or the installation feasibility of certain straps over plywood.

To help reduce cost and speed up installation, Simpson Strong-Tie introduced the MDCST — Medium Duty Diaphragm Tension Strap. The MDCST48 is a 14-gauge high-capacity strap specifically designed to carry tension across a CLT floor or wall panel joint. It installs with Strong-Drive SDS Heavy-Duty Connector screws.

With a characteristic tension capacity of 62.1kN, the MDCST48 can be overlapped to achieve double the load where space is limited. Notably, North American CLT manufacturers do not glue the edges of CLT plies together. To evaluate whether these unglued edges would affect the capacity of the SDS screws, Simpson Strong-Tie tested the MDCST48 on CLT. The calculations predicted that the strap’s tensile capacity would govern the characteristic capacity, and assembly tests validated the calculation model.