In this series' first two parts, we examined fence material and installation techniques. In this concluding part, we discuss the use of top guards and an alternative fencing material.
As homeowners struggle to find ways to enjoy the peace and serenity of their homes free from the fear of intruders, we increasingly see the use of top guards on fences.
Barbed wire and razor wire
A top guard is an overhang of barbed wire or razor wire along the top of the fence usually at a 45 degree angle. Where barbed wire is used as a top guard, there should be three strands of barbed wire spaced six inches apart. The supporting barb arms should be attached to the top of the fence posts and should be of sufficient strength to withstand a weight of 250 pounds applied at the outer strand of barbed wire.
The top guard should extend outward to hamper any attempts to circumvent the fence from the outside of the protected area. In certain neighbourhoods, top guards that face outward could extend over the property line of an adjoining neighbour and therefore this could prevent the homeowner from using barbed wire on the sides where there are occupied properties. In such circumstances, it would be better to use coiled razor wire as this has less of a projection into the adjoining property. In some instances, however, no projection into the adjoining property can be done and in those cases then the top guard should be placed vertically.
When razor wire is used, it should not be stretched taut but allowed to remain with some degree of springiness in the wire.
A top guard is not a complete deterrent against fence climbing; it works best against the casual or opportunistic thief.
Effectiveness of razor wire and barbed wire top guards
A common belief is that the topping of either barbed wire or razor wire will prevent people from climbing over the fence. For a determined intruder who has preplanned his attack, however, these devices do not prevent the intrusion.
This information is not to stop the use of either barbed wire or razor wire topping but to create awareness of its shortcomings and the realisation that a top guard is not all that can be done.
Razor spikes
A very recent entry on the perimeter protection market in T&T and an alternative to both barbed wire and razor wire is the use of razor spikes. These consist of a continuous double row of razor sharp spikes. The outer spikes are barbed and the narrow inner spikes have high penetrating power. Razor spikes are a topping to deter anyone attempting to climb over a wall. They are a formidable barrier but unlike razor wire they do not have that prison-like appearance and indeed have an aesthetically pleasing appearance. As a result of their galvanized coating, they have a long life and are very easy to install. In addition, they can also be painted to match the colour of the house.
As with many products, there are cheap imitations made with a lighter grade of metal that can easily be bent thereby defeating the purpose and greatly reducing the security effect. In addition, the imitations tend to be painted but not galvanized and so rust easily.
Wire wall
An alternative fencing material that is now available is wire wall. This comes in two versions: high security and medium security. The high security version is very difficult to cut without specialised tools and the closeness of the rails makes it difficult to climb without the use of climbing aids. The medium security version has wider spacing between the rails and so will allow gripping with fingers and toes. Notwithstanding the spacing, the thinness of the wire makes it extremely painful for someone to attempt to climb this fence.
From the viewpoint of preventing intruders from gaining access, wire wall is clearly superior to chain link fencing. The most significant factor in considering the use of wire wall is the extremely high cost.
Brian Ramsey, MBA,
Chairman, CISPS