Many South African home owners and businesses rely on electric fences to keep criminals out, but weaknesses in electric fence designs allow criminals to get through or over these barriers (also see: Beware the electric fence you install).
MyBroadband contacted security expert Riaan Coetzee from Fortis Pro Active Defence Solutions to find out how criminals get over or through electric fences.
Coetzee said criminals frequently climb over electric fences, because they are out-of-order or are not switched on.
“Criminals are very clever. They know that if an electric fence doesn’t make that little click-click sound, it’s probably off. Or if the wires are hanging loosely all over the place, it’s broken,” said Coetzee.
Roy Botha, director at Advanced Electric Fencing, said criminals use a method of hitting an insulator or two off the bracket, or strike the fence wires with a piece of wood to break some wires along the electric fence.
They then retreat and wait to see if there is any response. If there is no response after the alarm stops, they attempt to enter the property.
Criminals also throw rubber mats – like a car floor mat – over the fence to climb over. This may trigger an alarm if the fence is correctly installed.
Botha said using a blanket to get over an electric fence will not work with a well designed and installed fence.
“Each strand of wire is affixed with a compression spring allowing it to have some slack if force is applied – so much so that it will make contact with the wire below and set off the alarm in the scenario above,” he said.
Cutting a fence or using crocodile clips would not work either as apart from possibly receiving a hefty 9,000V shock, somewhere along the line one wire will make contact with another and trigger the alarm.
Some criminals fold parts of a rubber hose over the electrical wire strands to prevent them touching and setting off the alarm.
Weak electric fence design also makes it possible for criminals to bend the fence down, and then climb over without detection.
Botha said a three or four strand fence does not offer much protection. “Any electric fence with flat or roundbar brackets are also easy to get over as these brackets can be bent with ease.”
“Any fence with horizontal bits or even at a rather flat angle, say 45 degrees, form a natural ladder. Believe me, criminals scale high fences like Olympic athletes.”
The following video shows how easy it is for a criminal to climb over a poorly designed fence.
Douglas Deerans from Gido Electric Fencing said criminals target poorly-installed, low fences – four, five, and six strand installations.
He said they have seen criminals bending these brackets down. “They stood outside the wall, six-string flat brackets fitted inside angled out, and used either some sort of rope or shoelaces to wrap around the brackets and they gently pulled down simultaneously,” said Deerens.
Deerens said criminals have also started lifting the bottom two strands of fences fitted to 1.8-metre walls to slip through underneath.
The right wall is also very important. “So often people install an electric fence on top of a precast wall. That is merely false confidence. It’s way too easy to simply break a bottom slab and crawl through,” said Coetzee.
Load shedding is another problem when there is not enough battery power. “Extra batteries can buy you extra time should the power be off long enough to drain the existing battery,” said Coetzee.
Some criminals also create a short in the fence hoping it will malfunction, or that the owner will switch it off because of the irritation of the alarm.
How to create a safer home
Coetzee advised people to not only rely on an electric fence, but use multiple layers of security to keep criminals out.
“The fact is that there is no one fence that is criminal proof. Given sufficient time, odds are he will figure out a way to scale it,” said Coetzee.
He suggested the following setup to create a safe home:
- Perimeter – use an electric fence, preferably in combination with razor wire or another barrier to get over.
- Make sure your electric fence has an alarm, coupled with an armed response company.
- Install sensor beams in your yard which will set off an alarm. It may scare the criminals away and serves as an early warning system.
- Install cameras, if possible infrared cameras. It will give you valuable information about the criminals.
- Use sturdy, strong burglar bars and security gates. Avoid cheap stuff you buy at some hyper stores – it is child’s play to a criminal.
- Keep your gates and doors closed. Open security gates leads to nasty surprises.
- Inside the house, use additional security gates between living and sleeping areas to create further barriers.
In summary, Coetzee said the best possible electric fence is one that forms part of a layered defence system. “It should not be the only layer between you and potential intruders.”