The housing in Fairburn spans several eras, and each comes with its own pattern of exterior buildup. Older homes near the historic downtown square — many with brick or painted exterior surfaces — have had time to accumulate staining that builds slowly and becomes very visible on brick mortar lines and lower courses. Brick looks low-maintenance, but it develops biological discoloration over time, and the chalky white efflorescence that appears on older brick is a sign of moisture cycling through the surface.