“We hold these truths to be self-evident, that all men are created equal.” Those words, recognized as part of the Declaration of Independence are probably some of the best known in the English language. The created equal concept is not necessarily true when it comes to asphalt shingles, especially when comparing algae-resistance.
The best way to protect against algae from growing on asphalt shingles is with copper. Copper is basically the arch-nemesis to algae growth. An obvious example is a roof that has any type of copper fixtures on it, gutters, ridge vent, weather vane, etc. The area that is exposed to water run-off from the copper will not have any algae growth. The roof shingles color will be the same as when they were first installed. The non-exposed areas, not so much. In fact, depending on the region of the country and age of the shingles, they could be seriously discolored, making the roof look old and worn out.
Replacing or adding copper ridge vents can be a very expensive solution as well as somewhat overkill. Like all good things, there is a “sweet spot” when it comes to the amount of copper needed to stop algae. Not enough copper and algae will still get a foothold on the roof and spread. Too much copper doesn’t necessarily cause problems on roof shingles but it doesn’t increase the protection either. It just becomes superfluous.
Copper is the best way to stop algae growth. The best location is where it lives, on the roof shingles. There are several shingles available that are marketed as algae resistant shingles, or ARS. These shingles are manufactured with a portion of copper-fortified granules mixed in with the standard granules. These copper granules do protect against algae from growing. The only downside is there aren’t enough granules spread across the shingle. There are still large gaps between the copper granules where algae are free to grow.
The solution? Add the optimum blend of copper-fortified granules. Granted, it’s next to impossible to visibly examine a shingle and confirm the amount of copper granules it is manufactured with. But then again, there is no need to. Any shingle featuring Scotchgard™ Protector is manufactured with the optimum blend of copper granules uniformly spread across the shingle surface. This means the shingle is guaranteed to protect against algae streaks and algae stains.
Asphalt shingles may appear equal when placed side by side but unless it features Scotchgard™ Protector, resistance to algae is futile.