Composite panels also contribute to reducing construction costs owing to their simple and cost-effective assembly.

The fastening technique forms an integral part of the assembly. The fastening device must absorb the forces exerted by its own weight, snow, wind and temperature loading and discharge into the sub construction. The fastening device and the composite panels are currently not subject to any norm, which is why a General Building Supervision Permit issued by the DIBT (German Institute of Structural Engineering) in Berlin is mandatory. For this reason, only approved screws may be used to fasten the composite panels.

All approved fasteners are made from stainless-steel material no. 1.4301. A stainless-steel washer with a vulcanised EPDM seal must also be used.

Thread-forming fasteners or drill screws are provided for the assembly.

Thread-forming screws

Thread-forming screws form their own female thread when screwed into the sub construction. The composite panels and the sub construction must be pre-drilled for this.

Depending on the sub construction, a distinction must be made between screws with thread form A (coarse thread) and thread form B (fine thread).

  top

Thread form A

for thin walled steel and wood sub construction:

Fixing devices with a diameter of 6,5 mm are suitable for composite panels with thin walled steel sub construction (from 1,0 mm to 3,0 mm) and also for wood sub construction. Attention should be paid that the pre-drilling diameter is corresponding with the data of the approval. For wood sub construction the minimum dept of the screw is 50 mm and this has to be pre-drilled, according DIN 1052 - part 2, with a diameter of 4,8 mm.
 
 

  top

Thread form B

For steel sub constructions:

Fastening devices with a diameter of 6.3 mm are suitable for steel sub constructions from 1.25 mm to 6.0 mm and >6.0 mm. The spiral-shaped circulating notches in the thread reduce the screwing-in time in thicker sub constructions. The cylindrical threaded section of the screw must be fully screwed in the case of sub constructions up to 6 mm thick and thicker sub constructions of at least 6 mm.

The sub construction must also be pre-drilled. The pre-drill charts must be followed for each sub construction thickness.
 

  top

Fastening technique for composite components

Drill screws with support thread for steel and timber sub construction

The cost of assembly is reduced to one work routine when using drill screws with support thread. This means the pre-drilling, thread-forming and sealing are carried out in one operation.

The support thread (larger than anchoring thread) and the thread-free zone below the screw head guarantee a tight connection. As the outer shell of the composite panels always clamps optimally between the support thread and the washer, these drilled fasteners can be used in the roof area and on the water-carrying level (lower girder). The caps are removed when used in the upper girder.

Drill screws with support thread and a diameter of 5.5 mm are used on steel sub constructions. They have a maximum drilling capacity of 12 mm. The sub construction thickness is limited by the size of the drill head used in each case. The drilled fasteners for timber sub constructions have a diameter of 6.5 mm and a built-in drill head.

We recommend the following types of screw for various sub constructions:

  top

  top

  top

The fastener heads are visible on the inside of the building. If coloured fastener heads are desired for the outside, fasteners with powder-coated heads are available in a range of RAL colours.

Assembly

When processing the building components, composite panels and fasteners, the manufacturer's instructions for assembly and use and the building permits must be observed.

It is important that the fasteners are always screwed in at right angles to the roof and/or walls, as otherwise the washers will not lie completely flush on top.

  top

The air tightness of the connection is also guaranteed only by applying equal pressure to the washer on the outer casing of the component.

  top

Assembly equipment

The use of suitable tools is essential for proper, cost-effective assembly.
Only screwdrivers and/or drill screwdrivers with an adjustable depth may be used. This applies to all fasteners.
Impact screwdrivers may not be used in any circumstances. See permit Z 14.4-407 "Conditions for execution".
The following equipment is suitable for the different screws:

- drill screwdriver Di 600 for thread form A and B screws
- drilling screw set equipment CF 50 for drill screws with support thread and drill head
- drill screw set equipment CF 400 for drill screws with rise of crown (longitudinal joint fixing)