HOME INFORMATION

 

Outline Specifications for Security Fences

 

  1. Transparent fences are usually preferable to opaque fences or walls, as they permit you to have visibility to what is going on outside your premises. Conversely, it also allows people outside to witness anything occurring within your premises.


  2. The height of the security fence should ideally, not be less than 2.9 meters (9.5 feet) in height. This includes any marked extension at the top of the fence.


  3. Anti-climbing devices, such as razor wire or electric fencing - the razor wire should be coiled on single cranked extensions and used on the top of the fence, cranks to be facing outwards. The coils of wire are not to be supported by straight wire, as this provides leverage vital to climbing over walls and fences.


  4. Access must not be possible under the fence. The fence itself should be sunk into a concrete sill that is at least, 150mm deep.


  5. Limit, as much as possible, any changes in direction with the obvious exception being at corners. If you do require a slight change in direction, the angle should not be less than 130 degrees as these angles facilitate climbing at angle change points.


  6. The ground on both sides should be cleared as much as possible, thereby denying any intruder(s) cover to approach closer, whilst remaining undetected. If you have the space and budget, consider the possibility of a double perimeter with low wire entanglement in-between fences. We will discuss low wire entanglements later on in more detail.


  7. The bolts in the fence are to be burred over nuts or spot welded to prevent any dismantling.


  8. The fence is to be covered by active or passive lighting. This will be covered later in the lighting section.


  9. Gates in the fence are to be kept to a minimum. Any unused gates are to be kept locked at all times and checked periodically for any signs of tampering.


 

Outline Specifications for Security Gates

 

  1. Gates on a perimeter fence are to be constructed to the same standard as the fence.

  2. Hinges are to be designed to resist removal, or removal of the gate from the hinge. Locking is to be done by padlock and locking bar, both parts of the locking bar must be welded to the gate and frame, or to both leaves of a double gate.


  3. The bottom of the gates should not have a ground clearance of more than 51mm. Where this clearance is exceeded, then a concrete sill must be used to reduce this gap to 51mm.


  4. Remember: all gates not in use must be locked at all times and periodically checked for tampering!


 

Outline Specifications for Security Walls

 

  1. Walls are to be of smooth surface and constructed of brick, cement blocks or stone. Precast walling is not recommended as these can be easily broken and is not classified as a security wall.


  2. The wall should not be less than 3.65m (12 feet) high, topped with jagged material which should not protrude less than 51mm and where possible, combine this with razor wire or electric fencing.


  3. The wall must not contain any decorative edges or grooving which can facilitate climbing.


 

CCTV

 

In a CCTV camera for the home environment a fixed focus, wide angle system is better to install as the cost is cheaper than the more sophisticated pan, tilt, zoom (PTZ) cameras which require an operator. An important feature is to have a low Lux capability preferably 0 Lux so the camera will be effective at night time.

Lux is the unit of luminance which in layman’s terms is the operating light required for the camera to operate effectively. Below are some examples of luminance levels:

Luminance Example
10-5 lux Light from Sirius, the brightest star in the night sky
10-4 lux Total starlight, overcast sky
0.002 lux Moonless clear night sky with airglow
0.01 lux Quarter moon
0.2 lux Design minimum for emergency lighting (AS2293).
0.27 lux Full moon on a clear night
1 lux Full moon overhead at tropical latitudes
3.4 lux Dark limit of civil twilight under a clear sky
50 lux Family living room
80 lux Hallway/toilet
100 lux Very dark overcast day
320 lux Recommended office lighting (Australia)
400 lux Sunrise or sunset on a clear day. Well-lit office area.
500 lux Lighting level for an office according to the European law UNI EN 12464.
1,000 lux Overcast day; typical TV studio lighting
10,000–25,000 lux Full daylight (not direct sun)
32,000–130,000 lux Direct sunlight

 

Lighting

 

 

Perimeter Lighting

 

  1. Perimeter lighting is used to cast a strong light on both sides of a perimeter, directed outwards to produce glare towards the direction of an intruders approach.


  2. Light fittings should not be mounted on the perimeter. However, financial constraints mean that this is the only option available to most people. If you are in a position to mount perimeter lights separately from your perimeter fence then the lights should be no more than 5 meters apart. They should be angled so that the glare cuts the perimeter obliquely, illuminates it and the area beyond.


  3. Care must be taken with this lighting so that it does not interfere with motorist’s vision, or that the glare does not present any form of hazard to any vehicle.


  4. Solid walls should be lit on both sides, again this is governed by financial restraints and also whether your area has street lighting or not.


 

Area Lighting

 

  1. Area lighting is used to illuminate the area inside the perimeter, which an intruder has to cross to reach his destination, i.e. your lawn area.


  2. Area lighting should produce even illumination without dense shadows, every part of the area being covered should receive illumination from at least two directions - by lights spaced at an optimum distance in relation to mounting height; to produce an even spread of lighting. This obviously will differ in every case, as each persons garden will differ and will require a little experimentation by you to achieve the best results.


 

Flood Lighting

 

  1. Floodlighting is used to illuminate vertical faces e.g. buildings and walls, so that intruders are silhouetted against these surfaces. Intruders will cast shadows under this type of lighting and this can also lead to detection.


  2. Buildings painted in light colours help with this type of lighting to increase the effect. Light colours will reflect the light and increase the amount of glare generated.


 

Gate Lighting

 

  1. This type of lighting is to identify any approaching vehicle or pedestrian, however, it can also be utilised in most cases as part of, or already, an incorporated part of the perimeter lighting.


 

Topping Up Lighting

 

  1. Topping up lighting is used to illuminate small areas not covered by area or flood lighting which may otherwise conceal an intruder i.e. in your bushes.


  2. All dark spots are advised to be illuminated.


  3. In most cases, full scale security lighting may not be economically feasible, and simple adaptations of flood or topping up lighting principles could suffice. These could include:


  • Leaving certain interior lights on.
  • Illuminating porch and entrance areas ensuring that there is subdued lighting or none at all in the reception areas.

The diagram below illustrates the areas that can be expected to be covered by the various types of lighting and how these provide layers themselves.

These are the different types of lighting, usage’s and effects. These principles can be adapted, to suit each and every individual requirement and budget, as it can be built up over a period of time.

 

Recommendations

 

Fencing is recommended rather than walling due to the observation factor, the recommended fencing is known as Palisade fencing (See fig 1.2). It provides a strong physical barrier, giving good visibility and is very awkward to climb over.

Combining this type fence with razor wire or electric fencing on angled, cranked extensions angled outwards can maximise the prevention of entry. It makes this type of fence a very real and awkward barrier for any potential criminal. If you wish to enhance the effectiveness of this fence then having it spiked at the top and at various points on the length of the fence will make it more awkward to climb over, as illustrated in the photograph below.

This is the only type of fencing that is strongly recommended but it must be made of steel at least 3mm thick not thin sheet steel.

What if you already have an existing brick or precast wall that is only 6 foot high? People cannot afford to pull it down and replace it with Palisade fencing, so we require a level of adaptation and augmentation of the existing wall (See fig 1.3).

Lighting recommendations are dependent upon your budget but having critical areas such as entry points into the property, the garage and the home have to be prioritised. To minimise as much as possible to costs consider having all the lights on passive activators, the early warning these lights can provide at night could make the difference to maintaining your personal safety. According to research lighting is the least effective measure as a deterrent to house robbers but it enables you to have a warning and observation method of a presence.