Zinc roofing – white surface corrosion

Cause

Lack or rainwashing. Rain washing tends to be less effective on roofs with less than 15 degrees slope

Repair

  • wash down and begin a regular cleaning programme. Replace seriously degraded panels 

Cause

The roofing material is in contact with, or has run-off from, cedar or redwood, or timber treated with a copper-based preservative treatment 

Repair

  • wash down and begin a regular cleaning programme. Replace seriously degraded panels 

Cause

The roofing has run-off from translucent (PVC) sheeting 

Repair

  • wash down and begin a regular cleaning programme. Replace seriously degraded panels