Birds can cause considerable damage to virtually all types of roofing. Their droppings are extremely acidic and tend to eat away at roofing materials, particularly at any tar-based system, like asphalt shingles. Studies have shown that the life expectancy of a warehouse roof can be cut in half just by the continuous application of bird droppings. Bird droppings can also have a deleterious effect on air conditioning equipment.
There are other dangers to watch for with our feathered friends. Bird nests are often built in gutters and drains. When the drainage system is blocked, the continual application of standing water to roofing materials can cause serious damage. In addition, blocked gutters often overflow and cause water to penetrate the substrate or the roof of even the walls.
Yet another danger with birds’ nests is from fire. Because the nesting material is highly flammable — since it is made of up dried twigs, grasses and other natural items — when tucked next to electrical machinery or electric signs on a roof, the bird’s nest can quickly catch fire. Finally, birds often build nests in chimneys and in ventilation systems. Blocking the air flow in a chimney can have terrible consequences with smoke backing up into the building. In addition, blocked attic vents don’t allow the roof to breathe properly. Bird nests and their droppings, particularly pigeons carry many diseases, which can easily be spread to the interior of the building through the ventilation.