Probably the most effective method of keeping birds off buildings is to enclose roof and plant areas using bird exclusion netting, installed over the top and sides of shopping centre roofs, office buildings and even car parks.
When installed properly, it will prevent all but the smallest gulls from landing, roosting at night and nesting during the Spring and Summer months, while the birds will be prevented from settling and causing a build-up of drain-choking droppings for the remainder of the year.
Netting is the only method - when installed correctly - that will ensure pigeons cannot use features on a building, unlike deterrent spikes and wires which the birds will sometimes sit or even nest upon if it’s in a sheltered enough place.
Nets are typically secured to a 2mm diameter stainless steel cable that has been threaded through stainless perimeter fixings installed at 500mm centres around the perimeter of the area to be protected.
Pigeon exclusion netting is made from tough, UV-stabilized polyethylene with a mesh size of 50mm x 50mm.
Pigeon netting comes in black, stone or translucent colours and is much more difficult to spot on a building than you'd think.