An improper DIY roof cleaning could cause leaks by damaging the roofing material. Things like using too much water pressure on the shingles or applying a harsh cleaning solution could cause damage. If you do enough damage, you could harm the ability of the shingles or other roof materials to keep water out of your home.

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.

There are several telltale signs that your roof needs to be professionally cleaned. It's best to hire a professional as soon as you notice any indicators of wear to preserve your roof's longevity. Key signs to look for include:

• Moss, Algae, or Plant Growth: Look for moss growth, black streaks (which are often a type of black algae), or any other plant life on your roof's surface.

• Dirt and Grime Buildup: A general layer of dirt and grime can accumulate over time.

• Leaf Buildup: An accumulation of leaves, especially in the gutters, is a clear sign.

• Buildup Under Shingles: Dirt and debris can get trapped under the edges of your shingles.

• Shifting Roof Shingles: While this can indicate other problems, it can also be a sign that cleaning and maintenance are overdue.

• Comparison to Neighbors: If your roof appears significantly dirtier or different from your neighbors' roofs, that’s another sign it may be time for a cleaning.

Regular cleaning, promptly repairing minor issues, ensuring proper drainage, and using rust-resistant coatings help prevent recurring damage.