Oil canning is a visual phenomenon that can occur in metal roofing, causing panels to appear wavy or distorted. While it's a natural characteristic of cold-rolled flat metal panels, it can be concerning for some building owners. Let's explore the facts about oil canning and how to address it.

Oil Canning

What is Oil Canning?

  • A visual effect where metal panels appear wavy or distorted
  • Occurs in various metal roofing materials, including steel, copper, zinc, and aluminum
  • Most common in standing seam roof systems
  • Purely aesthetic - does not affect roof quality or structural integrity

Factors Influencing Oil Canning Visibility

  • Roof color and finish
  • Roof pitch
  • Temperature and sunlight exposure
  • Viewing angle and season

Common Causes of Oil Canning

  • Inconsistencies in roof substructure
  • Improper panel installation (e.g., twisting during placement)
  • Over-tightened fasteners
  • Structural movement
  • Uneven stress at fastening points
  • Temperature variations across the roof surface
  • Wide panel widths
  • Manufacturing issues (e.g., poorly adjusted roll formers)

Minimizing Oil Canning During Product Selection

  • Choose reputable manufacturers with well-maintained equipment
  • Consider narrower panel widths (12-16 inches instead of 24 inches)
  • Opt for heavier gauge materials when appropriate
  • Select panels with subtle configurations (striations, minor ribs, or planks)

Installation Best Practices to Reduce Oil Canning

  • Handle panels correctly during transport and installation
  • Ensure a level, plumb, and smooth roof deck
  • Plan panel layout carefully to minimize stress
  • Consider using a backer rod under panels for slight "bowing"
  • Monitor for oil canning throughout installation and address issues promptly

Key Takeaways

  • Oil canning is an aesthetic issue, not a structural or performance problem
  • Proper material selection and installation techniques can minimize its occurrence
  • Consult with manufacturers for project-specific strategies to reduce oil canning