Helical Flat Roof Fixing – Zinc – Timco

The Timco Helical Flat Roof Fixing is a hammer-driven fixing designed specifically for attaching structural 6mm plywood composite insulation board to flat roofing decks. Made from zinc plated high tensile steel, each fixing twists into the timber substrate as it’s driven home, which is what gives the helical flat roof fixing its holding strength without needing a pilot hole. No drill required. Just a hammer and a steady hand.

The helical thread design is the key to how these work. As the fixing is struck, it rotates into the timber rather than simply punching straight through. That rotational bite creates significantly more pull-out resistance than a smooth shank nail, which matters when you’re securing insulation board that will be subjected to wind uplift, thermal movement and foot traffic over time. It’s a smarter fixing for a detail that often gets treated as an afterthought.

Where Helical Flat Roof Fixings Are Used

These are a flat roofing staple. Roofers reach for them when installing warm roof build-ups, cold roof systems and inverted roofs where composite insulation board needs to be mechanically fixed to the deck before the waterproofing layer goes down. The range of lengths available, from 90mm right up to 270mm, means you can match the fixing to the insulation thickness you’re working with without resorting to some kind of structural improvisation.

Zinc plating gives adequate corrosion resistance for a fixing that will be encapsulated within the roof build-up and not permanently exposed to the elements. These aren’t intended as an external facing fixing, but within the system they’ll perform reliably for the life of the roof. The 8.0mm shank diameter provides the load capacity needed for flat roof insulation board without splitting the plywood deck.

Sold in boxes of 25, these are a practical site quantity for smaller flat roof jobs. If you’re doing volume, check our bulk pricing.