Biomatter on Your Roof: What Types Are There and How to Prevent Them

Typically, when discoloration begins to occur on roofing, some homeowners will brush it off as their roof shingles simply ageing. Although your roofing may change colour due to exposure to the elements, dark streaks on the roof can be an indicator of biomatter growing on your roof. It would be prudent to seek roof restoration services as leaving this biomatter to flourish can significantly impact the structural integrity of the roof. So what are some common types of biomatter that you would come across on your roof?


Algae is commonly mistaken for fungi such as mould or mildew. Nevertheless, despite the fact that algae also requires a moist environment to flourish, they are not the same types of growths. Algae is common in areas prone to humid climatic conditions, such as by the coast. But they can also flourish if the environment on the roof is conducive. The discoloration caused by algae will typically start off as minor dark spots. These eventually develop into vertical streaks that will extend on your roof. Algae is not particularly detrimental to roofing shingles. Nevertheless, they will affect the overall aesthetics of our roofing, and this can decrease the value of the home. If you have a reflective roof that functions to keep your home energy efficient, the algae can compromise the effectiveness of the roof. This is because the presence of algae will diminish the reflective performance of the roofing.


Another type of biomatter that may breed on your roof is moss. This is a form of non-vascular plant life that will thrive through the absorption of water through its leaves, unlike other plants that will obtain water using their root systems. One thing to note about moss is that unlike algae, it is capable of damaging your shingles over time. Since the moss retains water, you will find that your roof shingles will begin to exhibit signs of curling or lifting caused by the increased moisture content in them. Left unchecked, the growth of moss can eventually lead to leaks developing in your roofing as the shingles become worse for wear. It would be in your best interest to have the moss eliminated by roofers as soon as you spot it.

Tips to preventing biomatter from growing on your roof

  • Ensure that low hanging tree branches are trimmed away from your roof. This will enhance the amount of sunlight illuminating the roof, which minimises the levels of moisture that would make your roof a suitable breeding ground.
  • Ensure that debris on the roof is cleaned out on a regular basis. This is because the accumulation of leaves, twigs and other debris can provide prime breeding ground for moss and algae.