What is "oil-canning," and how do I cross-brake duct to prevent it?

Oil-Canning: The loud popping, flexing, or rattling sound made when large, flat sheets of duct metal expand and buckle under structural system air pressure changes. The Fix: Cross-braking. Before assembly, score or crease the flat sheet metal sections diagonally from corner to corner in a large 'X' shape. This adds physical structural rigidity to the flat face, preventing the metal from flexing back and forth.

[" Oil-Canning: The loud popping, flexing, or rattling sound made when large, flat sheets of duct metal expand and buckle under structural system air pressure changes. The Fix: Cross-braking. Before assembly, score or crease the flat sheet metal sections diagonally from corner to corner in a large 'X' shape. This adds physical structural rigidity to the flat face, preventing the metal from flexing back and forth.", '--']

Stop if

• Use this as training guidance. The foreman, approved drawings, project specs, manufacturer installation instructions, employer safety policy, and AHJ/code requirements always control the final answer.

Steps

• Oil-Canning: The loud popping, flexing, or rattling sound made when large, flat sheets of duct metal expand and buckle under structural system air pressure changes. The Fix:...

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