It has been a while since my last blog, and I feel blessed to have been so busy. I have a rainy day today and the opportunity to catch up on some projects and stray thoughts. Let’s discuss roof stains…

Roofs can become stained or streaked, we’ve all seen them, and it makes a roof look old long before it is due. Stained roofs are ugly and definitely take away from the curb appeal of a home or business.

Down here in the Florida Panhandle and the Alabama Gulf Coast, most of the roof stains you see are actually algae growing on the shingles. The algae latches onto and grows out of the pits and crevices of the granules on the shingle surface. Water travels down the roof, and so goes the algae right along with it. The algae won’t actually cause damage to your roof, it just looks older.

To prevent this, the shingle manufacturers have infused additives onto the surface of their shingles to prevent algae growth. Copper is the most common additive used, and is very effective until the copper deteriorates. Any time you start to add anything to a shingle, it adds cost. So some manufacturers add just a little to keep costs down, and some go all out to prevent streaks for a longer time. For instance, Atlas has teamed up with 3M Scotchgard for it’s Pinnacle Pristine shingle line, and has a great stain protection installed with minerals and copper encapsulated in a ceramic coating to slow the deterioration. Features like this will keep the shingles and therefore your roof looking great for a longer time.

Other causes of stains can be a direct result of trees overhanging or exposed metal accessories on your roof. The trees drop leaves, sap, seeds, and nuts. During the deterioration of such, stains get left behind. Often times exposed metals on your roof (pipe boots, vent covers, etc.) will leave what looks like a lighter streak or area down your roof. Sometimes this is a reaction of the metal coating on the shingle, but usually is the metal actually preventing the algae from growing as minerals come off of the metal accessory.

The roof washing industry is experiencing a renewed growth due to the rising costs of roof replacement. As a roofer, I am not at all against roof washing. I would, however, recommend speaking to shingle manufacturers regarding whether or not the materials are compatible, will void warranties, or will even help. It wouldn’t be great to pay to have your roof washed only to have it wreck your shingles or seals around metal screws. Consider the impact on plants and landscapes as it runs off, too. I’ll try to reach out to some shingle reps and get their take on roof washes for the next blog.

Thanks for reading!