Pressure washing costs in Madison

Madison's engineers keep a list of what ends up in the city's storm sewers, and a house is on it. Their water quality page names paint chipping off homes and pieces of roof shingle, right alongside brake pads, tire dust and fertilizer spread on the sidewalk. The page puts it plainly: the source of the pollution is us.

If your house sits in one of the city's local historic districts, the ordinance has its own say about how the outside gets cleaned. Under Madison's historic district standards, abrasive methods that can damage masonry and its mortar joints are prohibited. The list includes high-pressure water or acids on limestone or marble.

The same section bans sealants and water-repellent coatings on the face of the masonry. It also says brick that's already painted may be repainted, but brick that has never been painted can't be. Soft metals like copper and lead are to be cleaned with non-corrosive chemical methods, since abrasive methods easily damage their finishes.

Most of this counts as maintenance, and the standards say a project that's only maintenance doesn't need a Certificate of Approval. Masonry cleaning is the exception you'll want to know about. The Preservation Planner has to approve the method before the crew starts on your brick or stone.