Can I pressure wash composite siding?

Can I pressure wash composite siding?

Yes, but with real caution, since composite siding is more sensitive to pressure than many people assume. Most manufacturers recommend staying well under 1,500–1,600 PSI, using a wide fan nozzle, and keeping the wand at least 8–12 inches from the surface to avoid gouging or stripping the protective coating. Some composite products specifically discourage pressure washing altogether in favor of soap-and-water cleaning with a soft bristle brush, particularly older or uncapped composite lines that lack a protective outer shell. Using excessive pressure risks exposing the underlying wood fibers within the composite material, which can accelerate staining, mold growth, and void your manufacturer’s warranty. Always check your specific siding manufacturer’s cleaning guidelines before pressure washing, since recommendations vary meaningfully between composite product lines.