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.
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