IRONRIDGE Grounding Strap Expansion Joint Grounding Strap Expansion Joints are required for thermal expansion of rows exceeding 100 feet of rail. Insert Internal Splice into first rail and secure with screw. Assemble and secure Grounding Strap 3/8" from rail end. Slide second rail over Internal Splice leaving 1" gap between rails. Attach other end of Grounding Strap with hardware, and torque hex nuts to 84 in-lbs. Second Internal Splice screw is not used with Expansion Joints. Do not install module over top of expansion joint location.