You’ve probably wondered a thousand times what are those black stains on your roof. Many homeowners think their shingles are going bad after only a few years of being installed. Well, such is not the case. Algae is growing on your roof. Yes, thats right. Algae has started to take over your shingles, giving your family an eyesore in the meantime. Now dont worry too much. You are not going to have to spend thousands of dollars to repalce your roof. You can just call a roof cleaning st. louis company to come out and clean your roof for a fraction of the cost of replacement.