Galvanised steel roofing – corrosion at roofing sheet ends

Causes

The underside (back surface) of the edges of sheets have not been primed and do not get cleaned

There is a moist corrosive environment, as water likely to remain in the gutter  

Common

Listed under: finishes, metal, steel, paint, Roof, cladding, framing, durability, corrosion, rust, roof cladding, profiled metal

Cause

The underside (back surface) of the edges of sheets have not been primed and do not get cleaned

Repair

  • cut damaged roofing back to the next purlin; install short lengths of roofing, sealed to and lapping under the existing roofing by 150 mm. By the time corrosion is visible, damage is usually severe and is likely to require replacement. If the old profiled metal roof has met minimum Building Code durability provisions (it has lasted at least 15 years) a building consent is not required; if not, a consent must be obtained before reroofing. 

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Cause

There is a moist corrosive environment, as water likely to remain in the gutter  

Repair

  • cut damaged roofing back to the next purlin; install short lengths of roofing, sealed to and lapping under the existing roofing by 150 mm. By the time corrosion is visible, damage is usually severe and is likely to require replacement. If the old profiled metal roof has met minimum Building Code durability provisions (it has lasted at least 15 years) a building consent is not required; if not, a consent must be obtained before reroofing. 

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