Best Metal Roofing Screws & Fasteners (2026)

Washers, Coatings, Lengths & Screws Per Square

On an exposed-fastener metal roof the screws are the weakest link: a forty-year panel fitted with eight-year washers is an eight-year roof. The bonded EPDM washer is the actual seal, so cheap PVC washers that harden and crack become the leak source long before the panels fail. This guide explains what separates a good metal roofing screw from a bad one, why coating choice prevents rust streaking and galvanic corrosion, which length suits wood purlins, plywood decking, shingle recovers and steel framing, how many screws a roof needs per hundred square feet, correct drive depth, and the common mistakes that cause leaks.