When indoor humidity rises, hardwood boards absorb moisture from the air and expand across their width. In a properly installed floor with correct expansion gaps at the perimeter, that expansion is managed without visible consequences. In floors installed without adequate expansion allowance, or in floors where the expansion gap has been covered by baseboard without a shoe molding gap, the expanding boards have nowhere to go and begin to buckle, cup, or develop tight compression stress at the joints. Savannah's summers create exactly these conditions — sustained high humidity over multiple months that pushes wood moisture content well above the 6 to 9 percent equilibrium range that the National Wood Flooring Association identifies as the target for most interior environments. Homes in Ardsley Park, the Victorian District, Thomas Square, and Chatham Crescent — older construction with less airtight building envelopes — are particularly susceptible to humidity-driven floor movement because outdoor air infiltrates more readily than in modern construction.