You may become so frustrated with the look of moss on your roof that you contemplate whether to clean or replace your roof. Fortunately, you don’t have to go as far as replacing it. After cleaning the moss, you can use a chemical solution to keep it away. For further protection, trim branches that overhang the roof, as fallen seed pods and leaves on the roof allow moisture to collect, encouraging moss growth. Consider adding zinc-coated flashing to the roof, too. As rain washes across the zinc, it leaves zinc particles behind that inhibit moss growth.

You should not clean roof shingles if the roof has damage like missing shingles or low spots where water may accumulate. You should focus on repairing the roof before any cleaning process occurs. If you notice roof damage as you’re climbing on the roof to clean it, stop immediately. Call a roofing pro to make repairs. Cleaning a roof that has damage could lead to pooling water or water damage to the roof decking. The roof cleaning process removes mold and mildew, making the roof look better. It is not going to fix physical damage, though.

Clean the outside of your home at least once a year. If you live in an area with salty sea air, high levels of pollen, or an abundance of leaves in the fall, it's helpful to wash it at least two times a year. Frequent cleanings will allow you to remove debris and pests before they flourish into infestations, or cause mold and mildew.

While spotting a bit of algae on your roof may not bother you at first glance, it is certainly bothering your roof shingles. The presence of algae can cause decay and shorten the lifespan of your roof’s shingles, which can lead to much bigger problems down the road. While this issue may seem cosmetic at first glance, it goes much deeper than that.