The best way to clean a roof without damaging it is to opt for soft washing, or better yet, leave it to a professional roof cleaner. Soft washing involves a biodegradable cleaning solution being sprayed on the roof and gently rinsed away after it dissolves built-up residue on your shingles. 

A green roof is a roof design that includes a thin layer of vegetation on the roof surface. It’s an environmentally friendly option. Some green roofs may look like they have moss or algae on them, causing neighbors to suggest that you clean the roof. However, you should never try to clean a green roof, as any cleaning methods you deploy will likely kill the vegetation.

You should avoid using a pressure washer on any surface or item that could be damaged by the high-pressure spray, as some materials are too delicate to withstand the force.

Key items and surfaces to avoid include:

• Electrical Components: Never pressure wash electrical systems, as water can cause short-circuits and create a safety hazard. This includes utility meters, breaker boxes, electrical outlets, generators, and HVAC or air conditioner units.

• Delicate and Fragile Materials: Fragile items can crack, shatter, or be stripped by the pressure. Avoid pressure washing windows, glass, light fixtures, shingled roofs (especially asphalt), and stucco.

• Painted, Stained, or Sealed Surfaces: Unless your goal is to strip the finish, do not pressure wash painted surfaces, stained wood (like decks), or anything with a protective seal that could be stripped away. Be especially cautious with older surfaces that may contain lead paint.

• Soft Woods and Certain Decking: Delicate surfaces like softwood, composite decking, and antique or wooden patio furniture can be etched or damaged. If you must wash wood, use a lower-powered pressure washer with a wide-angle nozzle to prevent damage.

• Living Things: Never use a pressure washer on people, pets, or plants. The force can cause serious injury and will destroy landscaping.

If you wish to forego painting your shingles but still want to give them a fresh look, a deep cleaning is the first step. Clean off any debris from your roof and gutters, and then power wash your shingles to get grime and algae off. To take things one step further, you might even consider installing new gutters to give your home a bright new look.