Mid-Sheet Fasteners

Fastening is usually done by screws,inserted along the supporting internal purloins,spaced about 500mm(20in.) apart. ♦Along the edge purloin, the fastening screws should be inserted about 300mm (12in.) apart.

A hole must be per-drilled into each screw location. The diameter of that hole should be 2mm large that of the screw, to allow for thermal expansion movements. In case of dark colored sheets predrill even large holes, and use wider fastener washers.

Use of self-tapping or self-drilling screws is recommended.In case of wooden structures,suitable wood-screws should be used.AM the screws should be corrosion resistant.with at least heavy-duty hot-dipped galvanized finish.or stainless stre if used in an extremely corrosive environment).The screws should be 6mm(1/4in.)diameter.with length according to sheet thickness.type of washer and type of supporting structure.