How Birds Can Harm Buildings

Why Birds Flock To Buildings

Birds seek areas where they can roost and nest, well-protected from the elements and predators, with easy access to food and water. Many times, these shelters are beneath bridges, on building roofs, cornices, and HVAC units, among other electrical equipment found in substations. Each of these areas can attract hundreds of birds that leave behind both an aesthetic mess (droppings) and highly corrosive uric acid, which is found in their urine. 

Damage And Danger To Facilities 

In addition to the destructive power of bird urine, their droppings can carry and transmit pathogens such as bacteria like Salmonella and E. coli, as well as fungi like Cryptococcus and Histoplasma, and even viruses like West Nile virus. 

The urine component of bird droppings can have a pH of 3 to 4.5, which, after some time, begins to attack metals and roofing materials, solar panels, Dryvit finishes, vinyl canopy material, signs, and a wide range of other surfaces and finishes. Bridges and suspended walkways are particularly attractive to birds, protecting them from aerial predators while offering a safe and solid area for nesting. Given years of exposure to acidic droppings, the steel and concrete supporting structure of bridges begins to corrode and lose integrity, resulting in costly maintenance and repairs.

Beyond causing structural damage, birds may be responsible for up to 25% of power outages at utility substations. From nesting to arc flashes, electrical shorts, and attracting predators, birds can create large scale power disruptions that are time-consuming and expensive to repair. Birds seek out the protection of the transformers, switchgear, busbars, and other equipment that provides places for roosting and nesting. Unfortunately, their droppings can build up and create short circuits and cause overheating, forcing the substation to go offline. 

Risks To Roofs

As birds — primarily pigeons — populate building roofs, they can create a number of problems for the structure. A single pigeon can produce as much as 25 lbs. of droppings per year, and 100 pigeons can leave behind over one ton of droppings yearly. 

In flat-roofed buildings, the prolonged presence of acidic droppings begins to deteriorate the roofing material, and the presence of nesting materials like feathers may clog roof drains, creating the potential for roof failure. Asphalt and tar are particularly susceptible to damage from bird droppings. There have been reports of birds pecking at roofing material, creating points of entry for water and beginning the process of roof failure. In this case, birds can damage buildings both structurally and aesthetically.  

Impact On HVAC Units

HVAC units are generally placed on flat roofs and are very attractive to a flock of birds. While corrosion of the metal components of the HVAC system is a concern, the presence of pathogens in bird droppings on or in the vicinity of the unit is a hidden concern. Bird droppings are a witches’ brew of fungi, bacteria, and viruses that can pollute the indoor air and have a negative effect on indoor air quality. Pigeons prefer to nest underneath the HVAC units, as they offer a safe space for them to nest and protect their young from inclement weather. 

Messing With Signs

Now, most birds seem drawn to signs. Whether pole signs, channel letters, blade, or other types of signs, birds will try to establish a roost or nest in the smallest of spaces. If the sign is not hermetically sealed, birds will find a way in and begin to cause damage. Birds shed feathers inside the sign, leave acidic droppings, and may bring in nesting materials that attract and hold moisture that leads to rust, paint peeling, and more that ends in needing repairs or replacements. An annual inspection by the sign vendor will prevent any damage from proceeding further.

Power Outages and Electrical Risks

Birds can also introduce significant risks to electrical infrastructure. Research indicates that birds are responsible for about 25% of power outages at utility substations. Their nesting can lead to short circuits and overheating, which may disrupt power supply and incur hefty repair costs.

Birds are often drawn to transformers and other equipment found in substations, seeking shelter from potential predators. Unfortunately, their droppings can create hazardous situations that force substations offline, resulting in power disruptions that can affect thousands of customers.

Bird Watching

Birds can be dirty, and their continuous presence or nesting on a facility can damage our structures, creating unsightly messes and spreading harmful pathogens. Facility managers need to be aware of the damage birds are capable of to ensure facilities are properly prepared to mitigate any damage or prevent it before it begins.

Mitigation Strategies

To tackle the challenges posed by birds nesting on buildings, property owners should consider effective mitigation strategies.

1. Regular Inspections: Conduct routine checks of roofs and ledges to catch potential bird-related issues before they escalate.

   
   

2. Cleaning and Maintenance: Consistent cleaning of droppings and debris can greatly reduce health risks and prevent damage.

   
   

3. Bird Deterrents: Using bird spikes, nets, or other deterrents can effectively discourage birds from roosting in problem areas.

   
   

4. Habitat Modification: Altering the environment around buildings to make it less appealing to birds is another strategy. This can include eliminating food sources or changing landscaping to deter nesting.

Striking a Balance

While birds enrich our cities with their presence, their impact on buildings can be serious. The potential for structural damage, health risks, and power outages makes addressing these issues essential for property owners.

By understanding why birds are attracted to our structures and implementing effective strategies to manage their presence, property owners can protect their investments and ensure a safer urban environment. Proactive measures not only reduce maintenance costs but also enhance the overall integrity of our cities.

In summary, while we enjoy observing birds, it is crucial to manage the risks they bring to our buildings. Balancing our appreciation for these creatures with practical solutions to mitigate their impact can lead to healthier, safer urban spaces for everyone.