Galvanised steel profiled metal roofing – white rust
Listed under: metal, steel, Roof, cladding, durability, corrosion, rust, roof cladding, profiled metal
Cause
The zinc coating has corroded when water is trapped between sheets at laps and joints. This may occur during roofing installation or during storage before installation
Repair
- brush to remove the deposits with a stiff bristle brush – do not use a wire brush. Paint brushed areas with a zinc-rich primer and a metal primer, then apply at least two coats of acrylic paint
Cause
Insufficient rain washing. Rain washing tends to be less effective on roofs with less than 15 degrees slope
Repair
- brush to remove the deposits with a stiff bristle brush – do not use a wire brush. Paint brushed areas with a zinc-rich primer and a metal primer, then apply at least two coats of acrylic paint