It is possible to wash your own roof, but we don’t recommend it. First, getting up on any roof is dangerous without proper safety equipment, especially if wetting a metal roof and making the surface slick. Additionally, it’s easy to damage your roof or force water between roof seams if you use a power washer, which can lead to property damage. Hiring a professional roof cleaner will save you time, keep you safe, and ensure that your roof looks new again without damaging it in the process. Plus, roof cleaning is a relatively affordable home improvement project.

You could void your roof warranty using a power washer if you have a newer roof. With an older roof, you could knock loose older shingles. On the other hand, some people safely use a pressure washer to remove moss from a metal roof. Although you may want to use a pressure washer, the truth is that you probably don’t need it to knock moss loose. A garden hose and brush will do the job just fine and in a safer manner than a pressure washer.

Walking on the roof to clean gutters is unsafe and not recommended due to significant safety risks. It is especially dangerous on steep or slippery roofs, or if the roof is wet or covered in leaves, which increases the chance of a fall. In addition to personal injury, walking on the roof can damage shingles, potentially leading to water leaks. Instead of walking on the roof, use a sturdy ladder positioned on a stable surface to access the gutters. Be aware that using a ladder also carries risks, as it can be difficult to maintain balance while performing the work. You can also use ground-based cleaning tools. For safety reasons and to prevent damage to your roof, hiring a professional to clean your gutters is the best and safest option.

It may require stronger cleansers or chemicals, higher-pressure spray, or scrubbing to completely remove algae from a metal roof. Start with a mild cleanser; if that doesn’t work and you're comfortable doing so, use a stronger mix of ⅓ cup of laundry detergent, 1 quart of bleach, and 3 quarts of water to gently scrub the algae with a soft-bristled brush. If algae is present across large portions of your roof, doesn’t come off with gentle scrubbing and cleansers, or is in hard-to-reach areas, this may be a job better left to a pro.