Walking
Stramit® Top Hats are not designed for walking on. Residual oil may be present on these components from manufacturing. The use of appropriate cradles or cherry pickers is recommended. As a minimum follow these rules:
Never walk on purlins without safety mesh in place.
Always use a safety harness if walking on girts
Stramit® Roof Battens have a lightly knurled upper surface that assists in maintaining a foothold. Whilst designed to withstand foot trafiic load during installation Stramit Roof Battens are not intended to provide a walkway.
Stramit Ceiling battens are not able to sustain foot traffic loads and must therefore not be walked on.
Fixing/Connections
Always use the correct size and quantity of fasteners as specified by the design engineer. Pairs of screws at connections must be directly in line (parallel with the supporting member).
Laps
Structural laps for Stramit Top Hats require a minimum 10% lap length (i.e. 5% at each end).
End fastenings of top hats or battens should be at least 25mm from the section end irrespective of whether this occurs at the structure end or at an internal support.
Remember to allow for this additional material over and above the span length/s when specifying, ordering or cutting sections.
Top hat/batten overlaps (or non-structural laps) are recommended to be 100mm in length. In these cases structural continuity must not be assumed.
When connecting overlapping top hats or roof battens place foot onto upper section to nest sections prior to and during fixing. Laps must be fastened through both webs near both ends of the lap as shown below.
Welding
Stramit does not recommend the welding of top hats or battens. The heat produced in welding will affect the material properties of the high-tensile cold-formed steel used by Stramit in all its top hats and battens. In many instances considerable stress concentrations are likely to arise, even with good quality welding. In addition, welding will locally remove the galvanised coating leading to a potential reduction in durability.
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