Unfortunately, countless roofs are replaced annually not because they are failing or worn out, but simply because they are ugly with algae stains. Or worse yet, since they were algae stained, the uninformed owners assumed they needed to be replaced because of various, common sense and frankly usually just plain wrong reasons. This list includes acid rain, tar showing through the shingles, granule loss, tree droppings, improper gutter installation and the shingles are just “worn out” even though they may be less than 20 years old and sometimes less than 10!
So if you do replace it, what’s next? Well, you will have a nice pretty roof until the wind blown spores that are constantly bombarding your roof grow enough to become mature and start turning black. You will likely see them first just above the gutter line on the north side (or any side of your roof that gets little sun due to shade) or maybe around the roof vents. They will be faint at first, then become more obvious. Soon you will have spots in the middle of your roof and the black invasion will continue even in the dead of winter until soon you are right back where you were, minus the huge chunk of cash the new roof cost you.
Ok, but how long will this take? It is not uncommon to see roofs as new as just 5 years old start showing algae stains, but 7-8 years is common and by 10-12 years old it’s almost a guarantee. Homes with a roof section facing north and those with lots of shade will fall victim first.
Do I have any options? Yes! Shingle Brite will kill the infestations and leave your roof looking great for about 5% of replacement costs in most cases. Buy a new roof or have yours cleaned. Either way you have a beautiful roof, one just costs a lot less than the other.