Expansion Details for Flashings

 

Expansion Detail: Ridge with Soft Edge

ridge_expansion_soft_edgev1.2

 

 

 

Expansion Detail: Notched Ridge

ridge_expansion_notched_v1.0

 

 

Expansion Detail: Tranverse Flashing

transverse_flashing_expansion_details_v1.0

 

The basic design of the details shown above can be easily translated to expansion/slip joints on other flashings such as change-of-pitch flashings and aprons. The key features are that prime fastenings do not penetrate both flashing pieces, 3 lines of sealant protection are provided, and key areas such as fastener holes and the gap between the sheet end and the roof edge are given close attention.

If rivets are required to achieve a good fit of the two flashings, these rivets should not penetrate the roof cladding. In that manner, should the rivet fail in the future, weathertight failure is avoided.