Metal Hexagrid Fencing
To prevent chewing — by cats, and also by dogs, rabbits, and woodchucks — we gird the lower reaches of our cat fences with metal hexagrid fencing. This fencing, essentially stiff small-mesh chicken wire with a roughly 1-inch hexagonal opening, 20-gauge steel wires, and a black pvc coating, cannot be penetrated by potential chewers. Maximum height and length variation per roll 5%; expected life 20+ years.