A stress washer makes use of a source of power (either an electric motor or a gasoline engine) to pressurize water to create an ultra-sturdy stream of water that may deal with outdoor stains and dust with more power and fewer elbow grease than manual cleaning methods. The machine will pressurize water sourced from a standard hose to a designated amount of "pounds per square inch," or "psi." The high-pressure hydro-power is ideal for seasonal cleaning tasks, however earlier than you get started, brush up on your stress-washing fundamentals.