This heavy duty spike system in fitted in areas where seagulls and other birds tend to perch and nest causing a nuisance.
Its usually fiitted on roof ridges, on the edge of roofs where the birds sit and look down in seach of food and around chimneys where they may try and nest.
We use a strong water-proof glue that holds the spike system firmly in place in all conditions. They can also be screwed in place if appropriate.
Other bird deterrent systems are available. Ask for details.