Planing is ver effective but limited usage by the need to physically disassemble part of the deck to carry it out. Since planing removes the outer veneer of wood it also results in a change in physical dimensions of each board. Sanding is effective as a mechanical means for removing unwanted coats of previously applied finishes. It ca, however, damage the surface of the wood. On redwood and cedar sanding often results in an excessive amount of tannin resin bleeding.
Power washing is the mechanical method for cleaning and restoring decks most favored by contractors.
Power washers direct a pressure jet of water at the wood surface. This pressurized water is effective in removing dirt, mildew, algae and grey weathered reissue from most wood surfaces. It can also be effective in removing previously applied coatings. Power washers are available to homeowners through purchase or rent through many paint or home center stores. First time users need to be cautioned since excessive pressure can damage wood deck surfaces.