Common Roofing Problem: Unwanted Vegetation and Environmental Debris
Sprouting plants and a collection of leaves and dirt can happen anywhere on any roof system, but it’s most typical on ballasted systems because the ballast (i.e. rock) can trap dirt, giving weeds the opportunity to grow. Unwanted vegetation and environmental debris are caused by a lack of maintenance. Leaves, pine needles, and pollen typically gather at the roof’s edge and drain. Regular cleaning can eliminate the problem.
The biggest worry when there is unwanted vegetation on the roof is that it will clog the drain. But other, equally concerning problems can result too. A collection of dirt on the roof provides the opportunity for microorganisms to grow. Dirt can be deposited on the roof and once it rains, you’ve got a petri dish. Squirrels and birds can exacerbate the problem by depositing more debris in the dirt. If unattended, the problem can literally take root.
Growth of algae is common when there is excess moisture on the roof; it creates a safety hazard by making the surface slippery for rooftop workers.
The best way to prevent the accumulation of unwanted vegetation and environmental debris is to keep trees trimmed and clean the roof annually or twice per year.
If the problem exists, it’s best to hire a professional to come clean the roof. They have the equipment and training necessary to work safely near the roof’s edge and can identify if the debris has caused any damage to the functionality of the waterproofing membrane.