If you've noticed dark streaks, discolorations, or stains on your shingles, then your roof has most likely become a microbial buffet. While asphalt shingles don't sound very appetizing to humans, algae can feed on the limestone filler used in modern shingles. Because this is a slow process, many people put off removing this algae – but, although the damage may not be immediately visible, you should still get this mold cleaned off as soon as possible.
Isn't roof mold simply a cosmetic issue?
It's true that roof mold can be unsightly. And if you're trying to sell your home, you definitely don't want a streaky roof that detracts from the curb appeal of your house. But roof mold can cause much more serious problems as well.
Asphalt shingles contain limestone, which reduces their cost as well as increases their durability and their resistance to fire. But if mold is allowed to eat away at the limestone filler in your shingles, your roof is deteriorating faster than it should. Roofs with untreated algae will lose years from their lifespan as the structure of the shingles is eroded.
Dark roof stains can also have a negative impact on your bills. Most asphalt roofs today have an exterior UV coating, reflecting sunlight and helping to keep your home cooler. If this coating is covered up by algae stains, it can't do its job properly – instead, the dark stains absorb solar energy, raising the temperature inside your home.
Asphalt roofs of the past didn't need this kind of cleaning, so is this a sign of a faulty roof?
Before limestone was added to asphalt shingles, roof algae wasn't the problem that it is today. Roof algae doesn't mean your roof is faulty – it's a trade-off for the added benefits of limestone filler. Luckily, this means it's not an issue of having your roof replaced; having your roof periodically cleaned can eliminate this side effect of limestone.
Can't a homeowner just rent a pressure washer and clean it off?
While it sounds like an easy way to get your roof clean, the Asphalt Roofing Manufacturers Association recommends against pressure washing asphalt roofs. Pressure washing can damage the surface of asphalt shingles as well as wear away the very UV coating that you're trying to protect.
Instead, the best method to keep asphalt shingles clear of algae is chemical cleaning. And by calling a roof cleaning company like Roof Renewal Systems, LLC to treat your roof stains, you can ensure that the cleaning chemicals will be handled safely and appropriately, giving you a clean roof without damage to your paint, siding, or landscaping.Share