Stucco repair costs in Allentown

Parts of the Lehigh Valley around Allentown sit on limestone and dolostone, and that rock dissolves. The Pennsylvania Geological Survey has mapped sinkholes, depressions and caves across Lehigh County as part of a statewide effort to find carbonate areas with a history of sinkholes, and it did the same for Northampton County. The state's geologists say the process is natural but can be sped up by people, and that it's driven by water moving down through widened cracks in the bedrock.

The state's geologists add that karst is sensitive to how water is handled at the surface, and they point to stormwater runoff as something to manage with care. So on a stucco house over karst, where the roof water goes is part of the repair question.

Stucco has a long history here, too. In Bethlehem, the Historical Architectural Review Board reviews visible exterior work in the Central Bethlehem Historic District, which takes in many of the oldest buildings from the Moravian settlement. Its guidelines treat stucco as a weather coat for brick, stone or wood walls, sometimes scored to look like stone. When it comes to cleaning, the board asks for the gentlest means possible, usually low-pressure water with maybe a mild detergent and a brush. It warns that a high-pressure wash forces water into open joints, so think twice before you rent a pressure washer for an old wall.