Stop-ends are required at the upper end of all roofing sheets, on horizontal metal wall cladding and at the lower edge of all penetrations.
Stop-ends for trough and tray sections may be of two types, pull-up or dog-eared. Stop-ends for trapezoidal and corrugate profiles can only be of the pull-up type. Where the stop-end cannot be full height because of the profile design or is purposely left low to facilitate ventilation, the height of the stop-end must be at least 25mm.
The stop-end tool should be a proprietary tool designed for the product being used, with chamfered edges to minimise damage to the coating. Stop-ends to high tensile trough sections can typically only be effectively formed to the height of the S-bend in the rib.
Stop ending can distort the pan adjacent to the turn-up. Techniques such as standing in the pan being formed and supporting the pan on a flat surface can minimise this but it is difficult to eliminate, particularly with wide pans and high-tensile material.
The cover of over flashings should be sufficient to minimise water ponding caused by deformation during the stop-ending process. Deformation of the pan will also cause variation in the gap between notched flashings and the profile. Variations in the gap are acceptable, but contact with the edge of the flashing and the pan of the profile must be avoided.
A 'dog-eared' or full stop-end is made by cutting the rib back to the height of the profile so the material can be dressed and “wrapped around” 90°. It is not possible to dog-ear stop-end many profiles because of the shape of their rib.
To create dog-eared stop-ends:
Slit all ribs to a length equivalent to their height.
Cut away the tops of the ribs at a slight upwards angle and remove.
Insert the turn-up tool to full depth and turn up more than right angles.
Knock the dog's ears flat on a stop-end tool as shown.
Ensure the tray is lying flat
The rib height should be added to the sheet length when the material is ordered to provide an allowance for a full stop-end.
A 'pull-up' stop-end is not cut back but pulled up to the maximum allowable height without tearing the metal. No extra material allowance is required for a 'pull-up' stop-end.
Stop-ends for corrugate should be pulled up to the full height of the profile, and on low pitches at exposed sites, additional weathering may be provided by the use of filler blocks. See 8.8 Profile Closures.