This article or section is missing citations or needs footnotes.
Using inline citations helps guard against copyright violations and factual inaccuracies. (May 2008)
Perimeter fencing.
A perimeter fence is a structure that circles the perimeter of an area to prevent access. These fences are frequently made out of single vertical metal bars connected at the top and bottom with a horizontal bar. They often have spikes on the top to prevent climbing. Residential perimeter fences are normally made of wood about six inches thick, or a solid wall. Some fences may be string-like pieces of metal stretching across horizontally and vertically, creating a mesh of metal.
