No, you should not pressure wash or power wash roof shingles, including asphalt shingles. The high water pressure from these machines is too strong and can damage the shingles by forcing water underneath, loosening their adhesive, and causing them to fall off. A safer and better alternative is soft washing with a pump sprayer. To ensure the job is done safely without causing damage, it is best to hire a local roof cleaner.

Yes, moss can be dangerous for your roof if left in place to grow without treatment. The moss soaks up and holds moisture. Having a constantly damp roof could lead to problems with rot for the parts of the roof that consist of wood. Additionally, a patch of thick moss may draw insects and birds, which could damage the roof. Thick moss could block the roof’s drainage system. Water then may back up after a rainstorm and cause further damage that could eventually lead to roof repair expenses or the cost of roof replacement.

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.

Removing snow from your roof can help prevent ice dams, but the best thing to do is address insulation issues in your attic. If you do decide to remove the snow manually, you should always use a roof rake rather than a shovel. You shouldn’t climb your snowy roof in any circumstance, and roof rake allows you to remove the snow from the ground or a ladder. For the best results, remove snow as soon as possible after it falls.