Sealed “N” Safe’s Full Cavity Standing Seam Roof Insulation System features a 26-gauge, painted steel Insulation Rail. It is fastened to the bottom of the purlin to support the bottom flange of the purlin and the additional insulation. Then, the company’s 6-foot-long Thermal Blocks are centered over the top of the purlin. Insulation is placed over the Thermal Blocks, and SSR Panel Clips are attached on top of the insulation blanket. The assembly process is like a typical standing-seam roof.