Profiled metal roofing – staining

Cause

Run-off from lead flashings

Repair

  • if staining is from lead flashing runoff, carefully lift the lead flashing, paint the top and underside of it with appropriate primer and topcoats, then reinstall it 

Cause

Soot or particulate emissions from nearby chimneys or flues

Repair

  • wash the roof to remove soot or particulate deposits

Cause

Discharge onto the roof from a copper pipe, such as that from a hot water cylinder vent or from a pressure relief valve, or from copper piping in solar panels or air conditioning units

Repair

  • reconfigure copper vent pipes so they do not discharge onto the roof; insulate and seal all copper pipes to avoid run-off from the copper onto the metal roof or gutter 

Cause

Staining may be evidence of corrosion

Repair

  • treat as for corrosion