I was running a branch of the roofing-oriented distribution firm, JGA Corp., in my hometown of Jacksonville, Fla., when the first generation of popular “algae and fungus resistant” shingles hit the market.
I was running a branch of the roofing-oriented distribution firm, JGA Corp., in my hometown of Jacksonville, Fla., when the first generation of popular “algae and fungus resistant” shingles hit the market. This upgrade product created a lot of buzz there because of the semi-tropical climate that is as friendly to algae and fungus as it is to palmetto bugs.
A conventional asphalt shingle without any algae or fungus protection could be loaded with dark and ugly streaks within a few short seasons. The new A/FR shingles promised to remain clean for X number of years. The manufacturers wisely limited the number of years that the shingles would be protected from discoloration.
The manufacturers used different methods to fight the A/F beast and I recall zinc being a big ingredient, added to the surfacing granules. Made sense to me at the time since everywhere on a steep roof you saw a galvanized off-ridge vent you would see bright shiny granules below. The organisms that made the streaks simply could not live on the poisonous substrate of granules washed in zinc. Same thing with lead boots or even the rare copper ridge vents that existed only in the older parts of town.
As with many new creations the buzz settled down and the A/FR element became commoditized in many markets. You simply could not sell a shingle without it after a time. But the unfortunate thing about many A/FR shingle products of those days was that they only deferred the growth of streaks and discoloration. I have not done any scientific studies but have observed that, at least in my old hometown, the A/FR shingles would only stay clean several years longer than a new shingle without A/FR granules.
Suddenly there is new buzz being created by 3M with the introduction of their Scotchgard brand into the arena of sustained clean on shingles. On its website, the company states, “The Scotchgard™ Algae Resistant Roofing System from 3M guards against roof algae for up to 20 years … .” Read more about it here.
In my opinion it is about time the industry came up with a better solution to the problem of asphalt roofing “uglying out” years before it wears out. Tossing in a powerful brand like Scotchgard should move it forward with vigor. My guess is this solution has undergone more testing than one can imagine so it will likely meet its promise of protection. But time will tell if (a) contractors and consumers will embrace and pay extra for it and (b) if it will work in the real world.
In a residential roofing world otherwise consumed with the woes of the new construction market, the drama of the storm markets, and the otherwise lackluster pace at which all markets are returning to a good pace; it is really nice to have something positive to talk about. And Roofing Contractor will have lots to say in the coming months. Here are some links to roofing manufacturers who are rolling with the new granule from 3M: