Bird Post & Wire
Bird wire is very effective against pigeons and gulls
Bird wire, a post & wire proofing system, normally consists of multiple rows of 316 grade stainless steel posts, nylon coated stainless steel wire or stainless steel gull wire, crimped off and tensioned at a maximum of two (2) metres between posts. Tensioning is achieved through fitting a little stainless steel micro-spring for each pair of posts.
The configuration of the posts is to unsettle the pigeons trying to get onto the proofed ledge or parapet. This is achieved by making the heights of posts different in each row, starting at 90mm high for outside row and perhaps 150mm for the second row.