Galvanised plate

[Gareth J]

Fair enough, I guess that would seal and if you like the look it may make it worth it. You do risk exposing the ungalvanised, cut edge of a non complete sheet though.

Personally I'd never be able to justify the extra time/expense. Especially if paying someone else.

 

[Kent]

Fair enough can't see how any other way is much faster and unless you get an entrance that works with full sheet and don't need drilling you always have the cut edge
If it bothers give it a blast of xg- 90 cold galv or galvafroid