Which Screw Length?

Hi-Grip? What is it?

Hi-Grip is a revolutionary design in roof fasteners that overcomes the traditional problems with crest fixing metal roofing to steel or timber.

When roofing screws are placed on the top of the roofing profile prior to installation, an indent area sometimes forms around the screw due to the operator forcing down heavily before drilling commencement.
When the profile is fixed down with a non-Hi-Grip fastener this indentation remains around the fastener, causing water entry.

Hi-Grip is a secondary thread located at the top of the shank under the washer face. During installation the thread of the Hi-Grip is carrying the roof profile in an upward motion while the washer face is carrying the fastener in the downward motion.
The upward pressure at the Hi-Grip tends to straighten or reverse the indent made by the initial penetration, therefore preventing the possibility of water entry



Designed to achieve a number of functions:

The operator feels the thread bite, a clear signal to prevent over-drilling.

Restricts ‘over-drilling’ which leads to ponding or dimpling.

Grips sheet to provide ‘positive’ joint with EPDM washer.

Unthreaded shank prevents profile riding up during fixing.

Prevents sheet moving down shank when roof is walked on.

Extrudes metal around the fastener hole upwards making water ingress more difficult.