CHIMNEY BIRDGUARDS
As the name suggests, a bird guard is used to prevent birds, vermin and leaves or debris from entering a chimney or flue while allowing the flue to function to its full efficiency.
They are available in many forms, but the two most popular are the mesh type that normally fasten to the outside of the chimney pot or the wigwag style that fits snugly inside the pot. The bird guard must provide good ventilation and can also give added protection against wind and rain.