Preventing commercial roof animal damage is key to preserving the integrity of your building. In turn, ignoring animal damage can lead to expensive repairs, health issues and other negative consequences. Luckily, there are many ways to identify animal damage on your roof and many avenues to fix (and prevent) them.
This article discusses types of flat roof animal damage, their impact on landlords and pest prevention strategies.
Implications of commercial roof animal damageÂ
Why is it so important for landlords to quickly fix and prevent commercial roof animal damage? The most obvious answer is the cost of repairs. Depending on the damage, landlords can spend thousands of dollars on animal-related repairs. However, they may ultimately pay an even greater price if unaddressed damage leads to systems failures, code violations, liability or long-term damage.
Common types of animal damage on commercial roofs
You may ask what signs to look for in identifying animal damage on your commercial roof in Canada. Below are some common causes and impacts. You may spot easy-to-find problems during your periodic visual roof inspections. Professional roofers often find more hidden problems while on a maintenance call or twice-yearly roof inspection.
Chewed, torn or punctured roofing material
Rats, mice, squirrels and raccoons can cause commercial roof animal damage by chewing or clawing membranes and components can cause water intrusion, insulation exposure and premature membrane failure. The talons of gulls and other birds of prey can also puncture the roof.
Commercial roof animal damage can clog drainage systems
Birds, raccoons and squirrels build nests in roof drains, scuppers and gutter downspouts. Check flat roofs for blocked drainage, standing water, leaks and structural stress that may be caused by animals.
Insulation problems caused by animals
Some animals, especially raccoons and squirrels, will peel back membrane edges, nest inside warm roof insulation and cause other commercial roof animal damage. Without a watertight membrane, water can seep into the insulation. You may end up with leaks, mould and mildew. Beware that small patches of damp mildew can spread over time.
Animals can dislodge or damage rooftop equipment
Commercial roof animal damage can be caused by rodents and birds crawling under HVAC platforms or into ductwork. They may chew on wires, loosen panels or nest in fan exhaust systems. This damage may cause an HVAC failure, fire hazards or system inefficiencies.
Commercial roof animal damage from bird droppings
Bird droppings that build up on a rooftop are a serious problem. Pigeon and seagull droppings are particularly acidic. Repeated, long-term droppings can corrode metal flashings, HVAC coils, and supports, as well as degrade membranes over time. Imagine the corrosion from birds that nest (and drop waste) in the same place year after year, such as Canadian geese.Â
Migration of Canadian geese and commercial roof animal damage
In addition to roof damage, migrating birds also cause health and safety issues. Migrating Canadian geese become territorial during nesting, proceeding to dive-bombing nearby roofers. Birds also scavenge from near restaurants, dumpsters and other food sources. They may drop food on the roof, inviting more critters.Â
Health and safety hazards from animals on commercial roofs
We already mentioned bird droppings as a potential cause of commercial roof animal damage. Health code violations and fines are additional risks, such as if droppings enter rooftop systems and pipes. Add rodent urine and feces into the mix and your building may smell, have sanitation issues or cause illness. Waste can also introduce mites, fleas and other parasites into roofing systems.Â
Is there a liability?
Landlords face liability risks when animals intrude. For example, animal waste can be slippery, increasing hazards for roofers, Rooftop workers can also get stung by bees, wasps, or other stinging insects that nest on the roof. The worker may be allergic or may react in a way that causes a trip or fall.
Animal damage varies by the type of animals
 Telltale signs may indicate what type of animal has caused damage on a flat roof. Alternatively, if you spot a certain animal, you can check for associated damage. Once you determine the damage and the type of animal, you can take proper precautions.
| Animal | Behavior on Roof | Common Damage Caused |
| Birds | Nesting in HVAC units and gutters | Drain clogs, acidic droppings |
| Raccoons | Nesting in corners or tearing open membrane upturns | Membrane tearing, insulation damage |
| Rodents | Chewing wires and enter ductwork | Fire risk, insulation loss |
| Squirrels | Gnawing membranes or burrowing in insulation | Leak points, energy loss |
| Bats | Roosting in dark roof cavities such as chimneys | Droppings, odor, health risks |
| Insects | Bees or wasp nests in eaves or vents | Sting hazards and damage to seals |
Fix and prevent animal roof damage on commercial roofs
You don’t have to suffer from problems caused by commercial roof animal damage if you take the right steps. Three critical steps include maintaining the roof, having professional inspections, and acting on the roofer’s recommendations about how to fix and avoid problems. In addition, call a roofer as soon as you can if you see damage or suspect animals are on your roof.
10 prevention tips for commercial roof animal damage
The 10 steps below will help you address existing issues and prevent potential damage.Â
- The property manager should visually inspect the roof after major storms or seasonal changes.Â
- Trim overhanging trees to remove routes to the rooftop. Check trees for signs of gnawing, nests, droppings, and other animal issues.
- Identify and secure all access points, including gaps, vents, soffits, all drains and gutters, HVAC ducts and roof hatches, and hidden or unused doors.
- Install screens and animal-proof vent caps on HVAC intakes, vents, and other open penetrations. More sophisticated protective options include ultrasonic devices or motion-activated lights.Â
- Remove equipment, such as HVAC units that are no longer used or are left behind by prior occupants.
- Install protective barriers, such as welded wire mesh and animal-proof gates.
- Use bird spikes, netting, or gel repellents to keep birds away. Remove all nesting materials and address potential nesting areas. Remove accumulated droppings.
- Alleviate ponding water issues by working with your roofer to level the uneven areas.
- Consult professionals (wildlife removal services) as necessary.
- Keep up with maintenance and schedule twice-yearly roof inspections.
Remove the risks of animal damage
Commercial roof animal damage can cause an array of problems for landlords, so take care of them quickly. If not, the consequences can have serious impacts. Perform regular maintenance and schedule twice-yearly inspections to ensure animals don’t damage your roof, your pocketbook, or your health. If you suspect animal damage on your roof or to schedule a professional inspection, contact the experts at Elite Roofing for the #EliteAdvantage.
