The impact of algae on your roof

You have all seen mold growing on the roofs in Florida. Many of our customers have asked,” is this damaging my roof.” Having cleaned roofs for years I decided to get to the bottom of this topic, but unfortunately there are many proponents for both sides. I will present some of the facts and you can decide for yourself.

This mold is airborne, and grows well particularly on the North side of your building. It feeds on the crushed limestone that is put in your shingles, to give them weight. It stands to reason that if it is feeding on your shingle, your shingle is breaking down, but the mass the shingle is losing is very small and the damage you can cause climbing on your roof or taking a pressure washer to it may be much greater than the damage the mold is causing. (The exception to this comment would be moss, which has roots and does damage your shingles.)

Most shingle manufacturers recommend you use a chlorine solution at low pressure to kill this mold. A high pressure washer will blow off the protective aggregate on your shingle, decreasing its life. There are also alternatives to chlorine, such as oxygen bleach, which is less caustic to your plants, but more costly to your wallet.

With the amount of UV exposure we experience here in Florida our shingles get more and more brittle as they bake on the roof. The older and more brittle your roof is the more likely you will damage it by walking on it.

Those of you who live in gated communities may not have a choice whether you want to clean your roof or not, due to your home owners association’s regulations. For those of you who have a choice, figure out how old your roof is, or how brittle your shingles are. You can do this manually easily by just bending the corner of one. If it breaks off in your hand it is probably not time to wash the roof. Let the roof live out its life and put the money you would have used to clean it towards the time you are ready to replace it. Because the roof is brittle doesn’t mean it doesn’t have many years left in it. It is just a good indicator that if you are walking around on it you could cause damage.

As always estimates and consulting on your projects is free.

Krystal Klean looks forward to taking care of your building maintenance needs. Please don’t hesitate to call (904) 520-4001 with any questions regarding our services. Thanks and have a great day!

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