Temperature Changes - No Problem A unique feature of Supertech SSR - Standing Seem Roof is its ability to accommodate thermal expansion and contraction. The Supertech SSR features a unique concealed clip which has two distinct parts, the lower fixed part is fastened to the structure (purlin) and the upper movable part attaches to the specially designed roofing panels. The panels and the top part of the concealed clip are crimped togther either by mechanical seaming or specially designed mechanical locking. This ingeniousfixing arrangement allows for the roof top to practically "float" over the structure without being affected by temperature variations. Not only dose this concealed clip design accommodate thermal movement, it also allows the roof to withstand high wind uplift loads. Weather Proof Supertech SSR sheds water; moisture is locked out by mechanically sealed seams. Economical Supertech SSR permits a lighter support structure. it cuts roof maintenance costs by as much as