Polycarbonate spikes are effective and affordable
Another excellent five-star Bird-X product review.
I needed to keep pigeons off of the tops of brick and wood columns on my front porch. The plastic bird spike strips were easy to handle and included plenty of glue which has held up fine so far (about 4 months). The ledges I had to protect are fairly narrow (about 2 and a half inches) so a single strip has been effective. I’m very please with the inconspicuous appearence, easy installation and total effectiveness of this product.
By ‘NOLADave’ from Louisiana