Introduction
Zinc, which is cheaper than Lead, is used to replace Lead sheet roofs. However this material is NOT suitable for period properties.
What to look for
Zinc sheet can look very similar to Lead sheet, however Lead sheet tends to be thicker than Zinc sheet and Lead sheet is duller in appearance.
Zinc is fixed with zinc straps over the zinc ridges and is much more prone to wind lift. Zinc is often fixed with ferrous screws and these will rust. Once loosened, wind can easily remove a zinc ridge completely.
When to look
After high winds and at least once a year.
How to fix
Zinc should be fixed with non-ferrous screws. Being a light material, ensure that there is enough of a slight fall (run) on them, and designed to cast water away from the top of the wall outwards.
Avoiding creating problems
Be very careful when laying Zinc sheet to avoid creating dips and poor joints.