When it comes to hardscape, patios are a very low maintenance option. When constructed property, the stones will remain stable for years to come. This being said they do require a little bit of care on an annual basis to keep looking their best. Pressure washing is a quick and effective way to revive flagstone patios. After some time, moss, dirt and grime, and mold will begin to take over the stones. When that becomes noticeable, it is time for a wash!