Helical nails are a quick and reliable fixing for use in warm roof applications. Unlike traditional nails, they rotate as they are driven in, inducing a self-tapping action and consequently do not split or bounce timbers. Staifix products are available from builders merchants and other specialist distributors.

Super-8 headed helical nails secure plywood/insulation composite roof decks to timber joists. They are manufactured in three standard lengths which suit panel depths from 85mm to 160mm.

For applications with joist centres of either 400mm or 600mm, nails are typically installed at a minimum density of 6.9 per square metre.

The 18mm diameter head simplifies installation.