Power washing is generally safe for many types of surfaces, including concrete, brick, vinyl siding, and metal. However, caution should be exercised on more delicate surfaces like wood, stucco, and certain types of roofing materials. The pressure and technique must be adjusted accordingly to prevent damage. Additionally, the use of proper cleaning agents and the expertise of a professional can mitigate risks. Always assess surface conditions, follow manufacturer guidelines, and consider a test spot before power washing. When in doubt, consulting with a professional ensures safe and effective cleaning without compromising surfaces.