$100 over estimate and the end result was similar to spraying with a garden hose. They do come with a large commercial power-washer - but, for whatever reason, they do not do a good job of removing mold and even dirt. After they were done I could still scrape dirt and mold off the flagstone with my fingernail. Compared to other power-washing companies I've had out to various properties - this was not a good job. read more