The average price for deck cleaning services range from $80 to $400 for power washing, which is about $0.25 to $1.50 per square foot, as of 2015 and noted by CostHelper. Most companies charge a minimum or one-time fee for deck cleaning services, which can range from $100 to $250.
For a do-it-yourself project, deck cleaning supplies can cost $10 to $30, while renting a power washer can range from $40 to $75. Most companies charge by square foot depending on what part of the deck they clean. For example, cleaning the main part of a deck costs $0.25 per square foot while railings and stairs can cost up to $2.50 per linear foot.