Thermal Expansion: Curved Roofs

Provision for expansion should be provided in the same manner as required for straight lengths, but the configuration of curved roofs means that some expansion will be taken up by a springing of the profile further up, which results in less movement. When the total sheet length is considered for expansion, positive fixing should be used at the crown, and provision for expansion accommodated on the slopes.  Sealed and fastened end laps do not act as an expansion joint.