Roofing Construction Screw – Light Duty Composite Sheet to Steel – 16mm Washer (FF)

This light duty roofing construction screw is built specifically for attaching composite panel to light section steel purlins and rails. The self-drilling point removes the need for a pilot hole, which matters when you’re on a roof and every unnecessary step costs time. The split thread pulls the sheet down cleanly against the substrate, and the hex head with 16mm washer flange spreads the load across the panel face without cracking or distorting the composite. It handles steel up to 5mm thick, so it’s well matched to typical light structural framing found on agricultural buildings, industrial units and portal frame extensions.

The exterior plating is the part that does a lot of the quiet work here. It’s tested to 500 hours salt-spray resistance, which puts it in a different category to a standard zinc plated screw. For a roofing fixing that’s going to sit exposed to wind-driven rain, UV and the kind of condensation that forms on a cold steel purlin at 6am, that corrosion resistance genuinely matters. The finish holds up, the screw stays put, and you’re not coming back in three years to find orange streaks running down the cladding.

Where Light Duty Roofing Construction Screws Fit On Site

Four lengths cover the range you’ll typically need: 85mm, 105mm, 125mm and 150mm. Longer lengths suit thicker composite panel profiles or where the sheet overlaps a secondary layer. The 85mm is a tidy choice for thinner panel in a single-fix situation. Box quantity is 100, which is a sensible working amount for a standard bay or two of cladding without carrying more than you need up the roof.

The FF designation refers to the washer flange profile, which is designed to seat flush and even across the panel surface. A properly seated washer on a composite screw is what separates a weathertight fixing from one that leaks inside six months. Worth paying attention to on install.