Roof Cladding Expansion Provisions


The expansion of roof cladding depends on the materials, the constraints imposed by the fixing, the heat paths in the building and the actual temperature. The following graphics are indicative of favourable and unfavourable conditions for thermal expansion and suggest what these are. They show the lengths under both sets of conditions above which special provision needs to be made to accomodate thermal expansion.



  1. Where a roof requires oversize holes, only the portion of the roof outside of the recommendations require provision for expansion.  Normally this takes place towards the eaves
  2. These are guidelines only and special engineering of the roof, fixing or ventilation may allow greater spans to be used.
  3. These diagrams refer only to roof cladding screwed through the top. Secret or clip fixed roofs can move more freely if installed correctly and allow for using greater run lengths.
  4. The recommendations are based on preventing damage to the fasteners and are not a recommendation to prevent roof noise.


Clause Number: 
Revision Category: 
2 - Editing and rearrangement
Revision Detail: 

Edits to Favourable Circumstances for Controlling Expansion and Unfavourable Circumstances for Controlling Expansion:

  • Inserted y-axis lable: sheet length (m)
  • Removed Pan Fixing as unfavourable for expansion control.
Draft Clause: