The Crime Prevention Website

Share:

The following tables give a very basic description of the type of fences and walls that are or can be used to form boundaries of all types and provides comment about their individual security attributes.  What this section does not do is recommend any particular type, because you’ll either want to retain what you have and maybe improve it or choose your own from what is a very wide selection. You will also find that when you visit fence manufacturer’s websites, the choice will be vast.  Some fence manufacturers even produce composite fencing systems that use both steel and timber.  If you are buying a new timber fence make sure that it comes with a long guarantee against wood boring pests and wet and dry rot.

Visit DIRECTORY for products and services relating to advice in this section  

Timber fences and their security attributes  

TIMBER FENCES

FENCE TYPE

CONSTRUCTION

SECURITY IMPLICATIONS

Fencing panels*

Available in a wide variety of designs from DIY centres commonally to a height of 1.8m.  When a gravel board is added beneath a 1.8m panel it’ll hit the 2m maximum allowed under planning regulations. Most are are supplied with slotted timber or concrete fence posts, allowing the panels to removed for maintainance.

Higher quality systems of various designs and heights used for both domestic and commercial premises are available from specialist fencing manufacturers.  Look out for manufacturers offering a 25 year guarantee 

 

If your panels are installed into slotted concrete posts join each panel together with metal straps on the inner face to prevent the panel from being lifted up the concrete post slots.  Ensure that each timber panel is securely fixed into its corresponding timber posts.

Select timber panels where the pales/slats have been oriented vertically to reduce climbing opportunity.

A higher quality fence panel will use timber pales/slats that are at least 25mm thick.

Ideally, the fence panels should be the same height as the posts.  This will allow a capping rail to be run along the top to create a continuous chain of panels.  The capping rail should be of a suitable design to accomodate anti-climb toppings if required. 

Horizontal Board or Ranch*

These usually consist of timber posts and horizontal boards with small gaps in between each board. 

They are normally used as a boundary marker only.  Because their construction is similar to a ladder they can be easily climbed.

Vertical close-boarded*

A common fence construction consisting of vertical timber posts with 2 or 3 horizontal rails on which are nailed feather edge, plain boards or tongue and groove.  1.8m high fences normally have the posts no greater than 2.4m apart and use 3 rails.  The vertical boards should sit on top of a gravel board to prevent rotting.

The rails should be on the ‘private’ side of the fence so these rails cannot be used for climbing.  For increased strength reduce the gap between posts to 1.8m.  Instead of trellis topping, the top of each board can be cut at 45° to create a ‘shark tooth’ effect.  The fence can be further secured by weaving metal strapping between the boards as they are fixed in place.

Palisade (Hit and Miss) and stockade*

Similar in construction to vertical close boarded except that the boards are generally thicker and have gaps left between each board.  This type of fence is often used in places where a view beyond the garden is required or where there are very strong winds.

It is easy to force off the vertical boards from the rails because a lever can be put through the gap.  In vulnerable locations use galvanised (To BS EN 1461) coach bolts, nuts and washers to fix the vertical boards onto the rails, which will buy you a little more time.

Picket*

Similar in construction to palisade, but generally no higher than 1.4m.  Picket fencing less than 1m high is normally used as a boundary marker only to keep people and animals off lawns

Angled cuts on the top of picket fencing can stop people from sitting on it.  Heights of more than 1.2m with a thorny hedge can create a useful barrier.  If intending to use a picket around an opened planned front lawn check first with the local planning department

Wattle panels

A woven fence using stout vertical branches with thinner branches woven in between.  Available in various heights and widths they tend to be used more as a decorative fence or screen

If erected between timber posts and combined with a thorny hedge 1.8m panels can provide a reasonable barrier against the opportunist.  This type of fence can be used while a thorny hedge is maturing to a depth and height that is sufficient to prevent access by itself 

Chestnut paling

A temporary ‘roll-up’ fence that is used to protect young trees shrubs and newly seeded lawns.

This type of fence can be used as a temporary barrier while a thorny hedge is maturing to a depth and height that is sufficient to prevent access by itself.  This type of fence can be left in place as the hedge grows over the top. 

*For new timber fences always try to use a supplier that uses FSC certified timber that has been treated to provide protection against all wood-boring pests and all forms of wet and dry rot.  Some companies guarantee their products for 25 years.  All steel used in the fence construction and for the fixings should be either stainless and/or galvanised to BS EN 1461 with a service life in excess of 25 years.  

The security of all timber boundary fences can be improved by growing thorny plants through, around and or over them (although this will limit your ability to maintain them) and most can be topped with trellis and, for commercial applications, several other anti-climb toppings.  

 

Metal fences and their security attributes

METAL FENCES

FENCE TYPE

CONSTRUCTION

SECURITY IMPLICATIONS

Chain link

The galvanised or plastic coated interwoven steel mesh is supplied in rolls by the manufacturers. It is attached by clips or tie wires to straining wires and these are stretched between concrete or metal posts that have been set into concrete.  The straining wires are then tightened to create a firm mesh fence

Ordinary chain link fencing is climbable and the wire is easy to cut enabling the unravelling of the mesh to create a hole to climb through.  Many fences around school sites have the ‘short cut’ hole.  Chain link is useful as a stand for a thorny shrub.  A more robust class 2 anti-intruder mesh can be used, but it’s probably not worth it for the ordinary garden.  The mesh fence can be buried into a pre dug trench to stop things burrowing underneath.

Expanded mesh fencing

This fencing material is formed by punching a sheet of steel and then stretching the cut out to the required dimensions.  It is supplied in a number of patterns either galvanised or powder coated in a variety of colours.  It is usually supplied with its own metal posts, but sheets can be attached to timber posts.

This material is occasionally seen in gardens and it is more difficult to climb that ordinary chain link, because the holes between the metal sections are quite small.  It can be cut, but takes quite a while and leaves very sharp edges.  The tops of the panels are usually left unfinished and are also quite sharp.

Welded mesh fencing

The panels consist of vertical and horizontal wires that are welded together where they cross.  The panels are supplied galvanised, plastic coated or powder coated in a variety of colours.  The mesh is available in a number of different sizes and is supplied with metal posts.  Panels can be fixed to timber posts if desired for a domestic setting.

These fence systems are often topped with anti-climb measures when used to protect a commercial premises.

This type of fence has similar visual benefits as chain link and can be used to form a reasonably secure barrier where a view of the building or from the building needs to be maintained.  It is used mainly for commercial premises, but its use as a garden boundary has become more common.

Smaller mesh sizes using thicker wires (to prevent insertion of fingers to aid climbing and to slow down cutting) and the use of two overlapping sheets of welded mesh tend to be used for commercial applications.

Railing

Available in all manner of designs in cast iron and steel.  More often seen at the front of houses on top of dwarf walls. They often matched the design of gates giving access to the alleyways running behind the Victorian terraces. Many railings were removed during the war to supposedly help the war effort (a lot of the scrap from London was dumped in the Thames estuary!)

Tubular or box steel railing and fence panels should have a wall thickness of at least 1.5mm.

Many Victorian and Edwardian railings were designed more for aesthetic impression than security, although those with finial and spiked tops do present a reasonable barrier to intrusion by the opportunist. If you’re lucky enough to have them, restore them.

Palisade

Metal palisade fences are constructed on site and consist of ‘D’ or ‘W’ profile vertical pales with various top designs that are bolted or riveted onto horizontal bars, fixed between steel posts.  They are not really suitable for domestic gardens.  They are more often seen surrounding commercial yards and government buildings such as schools.  They are supplied either galvanised or powered coated in a variety of colours.  

It is possible to force off the vertical bars from the rails by inserting a long bar between the pales, such a plank of wood.  At my son’s old school the bottom bolts of two neighbouring pales were removed to provide a short cut gate!   This type of fence has its place, but regular inspections must be made to ensure its effectiveness.

The security of all metal boundary fences can be improved by growing thorny plants through, around and or over them.

Remember that all fences can be climbed over, so all you can do is slow the intruder down or make the lazy ones look elsewhere. 

 

True story

You will probably know that during the Second World War many thousands of tonnes of railing and decorative ironwork was given up for the war effort.  They were removed from schools, churches, public buildings and from walls in front of houses.  We also lost thousands of alleyway gates that used to stop burglars getting down back alleyways behind terraced housing.  What was it used for you might ask?  Well it seems that most of it wasn’t used at all, because it was so expensive to clean it up it was all but useless!  It turns out that one of the places it was dumped was the Thames estuary.  So much was dumped there that it allegedly affected ships’ compasses requiring the ships’ captains to call in the aid of pilot boats to get them to the docks – you couldn’t make it up!  

True story

Most of the railings you will see in our towns and cities are painted black, but this wasn’t always the case.  Having railings and decorative ironwork in front of your large town house was a sign of wealth in Victorian times.  They were often painted green to blend in with the colour of hedging and trees, but other popular colours, such as dark blue, chocolate brown and red were used to match the paint on the doors and windows.  The richest of residents even painted them with an early form of metallic paint using copper or even gold flakes!  When Prince Albert died, Queen Victoria started to wear nothing but black as a sign of mourning; a fashion followed by most of the population.  This was also followed by a frenzy of activity to paint everything black, including the railings.  This is why most of our railings are painted black, even those being installed today!        

Walls and their security attributes  

WALLS

WALL TYPE

CONSTRUCTION

SECURITY IMPLICATIONS

Concrete panels

 

Rarely used today in domestic gardens this type of wall consists of reinforced tongue and groove concrete slabs one on top of another slotted between concrete or steel posts.  They require little maintenance, but don’t score well aesthetically

These walls are very strong and cheaper to construct than brick or block.  Their light finish tends to attract graffiti on the public side.  Normally available in heights up to 2m.

Concrete screen

 

Consisting of pre-cast concrete blocks with moulded open patterns these blocks are stack bonded and require concrete or brick pillars for support.  Rarely seen as a boundary wall

Provides a readymade climbing frame and are not suitable as a defensive boundary.  Can be used to support defensive shrubs

Brick

 

Whilst expensive to build, a 2m brick wall with supporting piers will provide a long term low maintenance barrier.  Requires a substantial foundation and coping stones to prevent water penetration

A 2m brick wall with sloping coping stones provides an effective barrier against the lone intruder.  Unless a low brick wall to a front garden is topped with railing or steeply sloping coping stones it can be sat on.  This often happens in the vicinity of bus stops and leads to confrontation and calls to the police. Can attract graffiti. 

Where buttresses are required it would be wise to build them at full height as otherwise they could be used as a step to climb over the wall

Block and render

Cheaper and lighter to construct than a brick wall, but when rendered will provide a long term low maintenance barrier. Requires a substantial foundation and pier supports and a topping to prevent water penetration

A 2m rendered block wall provides an effective barrier against the lone intruder. Can attract graffiti  

The security of all walls can be improved by growing thorny plants on, around and or over them.

Remember that all walls can be climbed over, so all you can do is slow the intruder down or make the lazy ones look elsewhere.