Buckling:
The wood flooring becomes separated from the sub-floor. It usually is accompanied
by cupping and swelling.

Cause:
• Moisture caused by:
- Excessive job-site moisture
- A house left vacant with no ventilation
- Grade conditions
- Pipe leaks
- A wet slab.
Excessive moisture always is the main cause of buckling. Factors that may aggravate the problem include these improper installation techniques:
• For nail-down products, inadequate nailing, incorrect fasteners, incorrect sub-floor construction.
• For glue-down products, incorrect adhesive, insufficient adhesive, the wrong trowel, inadequate adhesive transfer (due to over-flashing or not rolling the floor), sub-floor separation or sub-floor contamination.
• Inadequate expansion space left by the installer.