Abstract: A steel roof deck diaphragm to provide structural rigidity to a building wherein loads of varying intensity can cause movement of structural members, which tends to generate noise when two members rub or work against each other. Corrugated sheets of high tensile steel are supported from below and span the distance between purlins, the corrugated sheets having over-lapping side edges and end edges and upper and lower surfaces. Non-metallic strips of felt form spacers positioned between the over-lapping side edges and end edges to prevent generation of noise resulting from relative movement of the corrugated sheets.