Why Algae Seem to Attack Some Roofs But Not Others

Even if you have a new roof, algae can darken and stain it to the extent that people will think it is unkempt and worn out. Algae seem to thrive on some roofs more than others, and there are reasons for this. If your roof is experiencing serious algae attack, then it might be for following reasons.

It Is Poorly Ventilated

Algae thrive in warm, moist areas—conditions that can easily exist on your roof if it is poorly ventilated. Proper ventilation ensures that the roof remains dry and cool because the air flowing through the roof will be unbalanced, and humidity will be high. Therefore, you should think about having a roof inspector evaluate your roof ventilation.

It Is Shaded

It may also be that your roof, or at least parts of it, remains under the shade for the better part of the day. This may be the case, for example, if there are tall trees with overhanging branches growing around your house. The shade prevents your roof from drying out completely, thereby providing algae with the moisture they need to grow.

It Is Dirty

Apart from shade and poor ventilation, accumulation of debris, especially of the organic kind, can also spur algae growth. This happens in two ways: first, the debris accumulation leads to dampness and provides the moisture for the algae growth. Secondly, algae grow best on organic medium, which means bits of leaves, paper, and small twigs will encourage their growth.

The Local Climate Is Wet

As you can see from the above discussions, algae need moisture to thrive. Therefore, if your house is located in a wet climate (whether it is cool or hot), then you are likely to experience more algae growth than if you were living in a dry place. Since there is nothing you can do about the climate, your only course of action would be to mitigate the algae growth by any means necessary such as the use of algae-resistant shingles.

Your Roof Is Poorly Drained

Lastly, you should also confirm that your roof has adequate drainage if it is experiencing high algae growth. If the gutters are undersized, damaged, or clogged, then they may be letting water stagnate on the lower parts of your roof. This moisture may be responsible for algae growth on these lower parts of the roof.

It's clear that many factors contribute to the growth of roof algae. Therefore, if you aren't sure of the cause (and don't forget that your roof can have several of these factors), then you should call for a professional like GBS Enterprises Roofing.