Insofast Ltd
Insulation Fixings
Structural Repair
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Flat Roof Fixing

General Quick Guide

  • Quick and easy to use
  • Reduced cold bridging
  • Fewer fixings - reduced labour
  • Alleviates splitting of joists or rafters
  • High degree of fire resistance
  • Shallow dome head leaves no sharp edges
  • Fix with hammer or rapid SDS drill adapter
  • Dependable performance


A spiral shafted one-piece helical anchor with an 18mm dome head suitable for insulated flat roofing applications. The anchors can be hammered in manually or by using a standard SDS hammer drill with a dedicated adapter.

The hardened cutting blades make the anchors quick and easy to use, with a self-tapping action providing a permanent, secure anchor.



The thermally-efficient spiral shaft has a much smaller cross sectional area than that of a solid shaft of equivalent diameter to minimise disturbance to the materials being used, reducing cold bridging potential and avoiding splitting or other damage.

ISF18 anchors can be used without the need for pre-drilling, are as easy to use as conventional nail fixings and provide a firmer fix with reduced effort.

Suitable for all types of roofing board having a 6mm thick ply-face including Kingspan, Celotex, Xtratherm, Recticel and others.


Product Specification

Material Zinc Plated AISI 1008 Steel Austenitic 304 Stainless Steel
Diameter of Head 18mm
Diameter of Shank 7mm
CSA of Shank 9mm≤
Pitch Accuracy < 0.5%
Typical Load 1mm Defln 681N (softwood joist)
Fixing Centres 600mm x 400mm per board (Roofs up to 10m high)
Available Lengths* 145mm (panel depth 85-110mm)
170mm (panel depth 115-135mm)
195mm (panel depth 140-160mm)
220mm (panel depth 165-185mm)

220mm is available in stainless steel only

* Based on minimum 35mm rafter / joist embedment

Download Data Sheet

Page updated 20th Jul 2011, 19:51
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KKM Buildings
Old Reservoir Road
Company No. 07455797, Registered in United Kingdom
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