Limitations of Bird Gels
Case Study — Staining of Stonework
Hardened tack from use of an anti-bird repellent product
In these photos, the black marking is the hardened tack, from use of an anti-bird repellent product. The atmospheric dirt combined with the temporary tack from the gel and bird excreta caused the mess, as illustrated here.
In our experience the effective life of such gel products is maybe, six months. The resultant mess - many years.
The property maintenance company contracted to clean this building before trained installers birdproofed it, were unable to remove the gel from the stone. Porous surfaces are the very worst for this. On non-porous surfaces and before it reaches it's end-life, such gels can 'run' and drip down walls when the contact surfaces get very hot.
For long term proofing solutions, use proven products and systems shown in this site.