Rot, holes, corrosion, leaning, and age are five signs that fencing needs to be upgraded. Rotting or holes in timber or wrought iron fencing, corrosion that causes iron fencing to deteriorate over time, a fence that is leaning indicating weakening internal structure, a fence that is no longer aesthetically pleasing or providing security due to old age, and a tree growing through gaps in the fence that can damage it all indicate it is time to upgrade fencing.