Concealed-fixing, also referred to as secret fix, is designed for very low pitched roofs. Because clips under the sheet hold it down, the sheet is not punctured with fasteners, and remains completely watertight even at a very low slope. The securing clips are pre-fixed into the purlins and the sheet is mechanically snapped onto the clip. As a concealed fix sheet can also expand and contract over the clips as the temperature changes, this system is ideal for long spans on industrial, commercial and retail buildings.
SAFLOK 700 is a concealed fix sheet profile with an effective cover width of 700mm. It is an angular int erlocking standing seam trapezoidal rib profile, and is usually roll formed on mobile mills on the building site.

The SAFLOK 700 clip incorporates a dual action component to positively hold down the male-female joint on every third rib, and an anchor to clasp the two inner ribs. Every rib is therefore secured, making it fully interlocking. It is essential that the male rib is directly engaged to the underside of the clip.
Clips for Aluminium Material:

  • An Aluminium clip is a necessity when using Aluminium Material.
  • When using Aluminium material on galvanized steel purlins it is recommended to make use of an isolation tape to prevent the bridging of the two dissimilar materials. The recommended tape is a “Denso LDP 300” or similar. Should the two metals have direct contact it will ultimately result in
    the manifestation of galvanic corrosion. The service life of the Aluminium will be compromised.

saflok clipping


material options

Safintra 0,50mm thick SAFLOK 700 ColorplusĀ® AZ150 interlocking roof sheeting fixed to steel internal purlins at 2000mm, and ridge/eaves purlins at 1700mm centres using SAFLOK 700 clips which must be screw fixed to steel purlins with class 3 wafer head self-tapping screws, all in accordance with manufacturer’s recommendations.
The sheeting will be a double interlocking concealed fix “SAFLOK 700” profile as manufactured by Safintra Roofng, roll formed in continuous lengths from certified G550 steel or aluminium 3004 H14.
The profile shall be roll formed with 4 ribs and centres not exceeding 233mm and a cover width not exceeding 700mm. The male rib is to include spurs to ensure a double interlocking action with adjacent sheets. The minimum sheet depth will be 41mm. Two stiffening ribs are incorporated in each pan.
We do not recommend using Saflok on a roof pitch exceeding 5 degrees due to the possibility of oil canning.