Bond, English

This is one of the commonest method of constructing a brick wall which is more than ½ a brick thick and consists of alternating courses of heads and stretchers.

English bond brickwork

English bond brickwork

The minor wall building materials

Metal

Though important in building is garden use is rather limited but can if used carefully can be very effective. The term metal encompasses a vast range of material, many used since ancient times, and the suitability of a particular one will depend on the individual use planned.

Reinforced concrete

This material combines concrete and steel to create a material with excellent compressive and tensile strength. This provides the potential to provide some very graceful and elegant structures but the complex nature of the material means is design and specification requires specialist expert knowledge.

Concrete reinforcing should not be confused with crack control in concrete, by weldmesh or polypropylene fibres, which serves a very different purpose.

Plastic

Traditional plastic has not been used a great deal in garden construction but the vast range of different forms of plastics means it has great potential. It has the advantage that it is very rot resistant, can be moulded (and some can be machined), pre-coloured and even some is made from recycled materials means it is beginning to be used for more than pond liners and roofing sheets.

Glass

Used for hundreds of years, recent developments in glass technology means this is a material with great future potential.

Peat blocks

Traditionally these have been used to make raised peat beds, but have they have fallen out of favour in recent years as a result of the environmental concerns around peat harvesting and use.

Peat block wall

Peat block wall

The main wall building materials

Brick

Reclaimed brick walling

Reclaimed brick walling

One of the oldest and most durable building materials; its variability, flexibility, durability and strength has made a ubiquitous walling material. Traditionally made from dried earth the centuries of use and development has lead to a very sophisticated produce now mass produced in millions each year in the UK alone.

The earliest bricks were probably made of mud and date back at least 5000 years, and probably considerably more. Modern bricks are still normally made from fired clay (a natural extension of sun-baked mud) but they now come in a vast range of colours and surface finishes. It must be remembered that most facing bricks, while very strong are damaged by frost if their exposed surfaces are saturated with water. The only real exception to this is engineering bricks which are not as absorbent as facing bricks, but are only available in plain red or blue.

 Concrete

The use of concrete dates back at least 2000 years; it was used extensively by the Romans and there are Roman writings on its mixing, placing and use. Though its use has waxed and waned with changing fashions is seems every new generation re-discovers it, finding original uses for it.

Years of use and study have meant that what may appear to be a very simple basic material has become a very complex subject. What is frequently not appreciated is concrete, while having excellent compressive strength1, has so little tensile strength2 that is it regarded by engineers as having none.

Stone

The stone mason is one of the oldest trades and stone walls have been found wherever stones can be sourced. The earliest were probably dry stone walls built from stones found laid on or near the surface of the soil.  The durability and effective ness of these can be seen from the miles of dry stone wall which snake over the North Yorkshire Dales, where the shallow topsoil means the stones could be sourced by gradually picking up stones laid about the fields. Once metal tools had been invented stone could be cut, worked and polished allowing the creation of the pyramids and temples of the ancient world.

Wall detail at Dornoch Cathedral

Wall detail at Dornoch Cathedral

Stone comes in a vast range of forms and this determines it suitability for building and what results can be achieved. As one of the main costs of stone is haulage, traditionally it was sourced close to where it was to be used so lending distinctive local styles to walls.

 

Timber

Though not as durable as stone or brick, its easy of working and availability has meant it has long been used as a building material. It has also has other advantages over brick and stone work: it is a lot lighter, possesses tensile strength2, can be readily coloured with stains and paints, and although it does weather it is unaffected by frost.

Timber pole walling

Timber pole walling

Wood is though a very variable materials depending mainly on the tree species it comes from, but also the environment the tree grew in and the part of the tree it is harvested from. When used in construction this can lead to concerns about its structural strength and for this purpose it is “stress graded” but in a garden context the size of the timbers chosen for aesthetic considerations means this is unlikely to be important.

Notes:

1)      Compressive strength is simply the ability of a material to resist being crushed.

2)      Tensile strength is simply the ability of a material to resist being pulled apart, something that brick, concrete and stone walls actually lack. Hence the need for arches or solid lintels over openings in walls.

Parts of a Wall

Garden walls are constructed from 5 distinct elements:

Parts of a wall

Parts of a wall

Subgrade

Foundation

Walling materials

Mortar

Coping

 

The first, the subgrade, is the ground the entire structure stands upon and so its stability and load bearing ability determines on whether the wall is going to remain standing. For these reasons the wall foundation should be onto undisturbed ground that has not been built up from material such as old construction rubble or compacted hard core. For the same reason sufficiently deep so that there is no risk of frost and therefore frost heave.

The foundation of the wall is normally concrete and acts to spread the weight of the wall. Historically wall foundations could vary from nothing at one extreme to quiet complex structures and this depends more on the ground conditions and the builder/architect than the date they were built. A roman building could have a concrete foundation not unlike a modern while a country cottage built in the last few hundred years may be built straight onto the topsoil.

The walling material is the bricks, stones, etc. which forms the walls.

The mortar is the sand based material generally used between the pieces of the walling material and it serves the function of keeping the pieces of walling apart. It does not hold the pieces together, so walls have no tensile strength, but instead keeps them apart; so stopping them wobbling and stabilising the structure. The sand itself is held together by incorporating lime or more normally now cement to prevent it being washed out of the joints.

The coping tops the wall and protects it from becoming saturated with rainwater.

Walling Materials

Brick wall detail at Lartington Hall

Brick wall detail

Historically walls have tended to be built from the nearest suitable materials and this has to very individual regional building styles. Since the advent of modern mass transport this has begun to be broken down; except where local planning restrictions have protected it. That is not to say the local traditional building style has to be followed slavishly, if any is discernible in the first place, as often the use of a contrasting material can be very effective. Making a clear demarcation between the old and new; always fair better than a poor match.

Traditionally walls have been associated with bricks or stone pieces with a mortar between them to stabilise the structure. As a building technology this is a very old one; and was well established by the time the Romans combined this with the arch allowing them to create their major engineering feats. The individual units that create a wall tend to be small, partly from practical considerations and partly from aesthetic ones. The small individual units imparts great flexibility into any design for a wall, allowing the same wall to be both straight and curved at different points. Its appearance can also be uniform if the same material is used throughout or broken up if the sizes and/or colours of the materials are varied.

Walls though don’t have to be brick or stone; the material used for their construction is only limited by the designer’s imagination. Concrete, timber, recycled bottles and wire cages filled with cobbles have all been used to make walls. The choice of materials dramatically alters the effect wall will have within the garden, as will its detailing and height.

When choosing the material to build a wall the range of possibilities is vast, with hundreds of different bricks alone to consider. When deciding on a walling material a number of factors have to be taken into consideration:

What materials have already been used?

How much are you prepared to spend on the wall?

What is the danger of frost damage?

How solid does it need to be visually?

How high does it need to be?

What if anything does it have to support?

How important is it to the appearance of the garden?

What finished appearance is wanted?

What shape is it going to be?

What is the purpose of the wall?

While this list won’t make the selection for you; it will narrow down the search, help focus your mind and hopefully broaden your mind to less obvious possibilities.

Types of garden walls

Free standing

The simplest walls are free standing and these are normally used when boundaries are walled. In the UK garden walls above 2 metres high, unless they face the public highway when its 1 metre, require planning permission. That said this is only a basic guideline and local rules or covenants can often apply so before you start any work you should make a quick call to you local planning officer. In practice these heights are quiet sufficient and you would need a very good reason before the authorities will allow you to exceed them. When considering the height of the wall you have to remember that if the ground level is lower at one side of the wall than the other the measurement is taken from the lower side and the height includes all parts of the wall including pillars, copings or anything else attached to the wall.

These days most garden walls are either ½ or 1 brick thick; though older gardens will often have 1½ or 2 brick thick ones. The choice of wall thickness will in the first case be determined by what is needed to ensure the wall is stable but then a thicker construction may be chosen for aesthetics. Clearly the thicker the wall the more expensive it will be and all walls are expensive, so a good reason is needed to make a wall thicker then it has to be. An excellent guide to the wall thickness needed for a particular location in the UK can be seen on the Government’s Planning Portal.

 Heated walls

 The idea of using a garden wall to provide heating may seem strange and very wasteful to us now, but at one time this was state of the art gardening. The walls were built with fireplaces spaced along their length and the chimneys took the form of brick flues snaking up through the walls. The hot smoke and gases from the fires passed up the wall flues, heating the wall as they went. Many are still seen in old large estates around vegetable gardens where they heated lean-to greenhouses built against them. They are easily spotted by the chimney post along the top and are usually thick and generally two stories high.

Heated Garden Wall from The Book Of Garden Management by S. O. Beeton

Heated Garden Wall from The Book Of Garden Management by S. O. Beeton

 Retaining walls

This is the commonest reason for walls to be used in a garden. Where a garden requires a change in levels, either by design or necessity, a wall is the most efficient method of achieving this. The wall must be sufficiently strong to support the material it is holding back and in the majority of circumstances this is achieved by the weight of the wall.

In most cases in the garden the amount of material being supported by the wall will be relatively small and the potential danger from the wall failing will be small. In practice, the aesthetics of the wall design will mean it will be sufficiently strong, but if the wall is going to need to be higher expert advice should be sought. Because by their nature retaining walls cut across the natural drainage of the ground there is a danger of water building up behind retaining walls. This can weaken the soil around the wall foundation and therefore weaken the wall. To prevent this drainage must be provided behind retaining walls which empties out through small holes in the wall called weep holes.

 Ha-ha

 The 18th century saw the English “leap the garden fence” and develop the English landscape Garden style where countryside became the garden, all be it in a much stylised form. To achieve this, the garden boundary had to be hidden to allow the garden to visually run seamlessly into the surrounding fields. To achieve this; the wall is set into the ground below eye level. In practice this is a very expensive process, generally requiring large amounts of earth to be moved in addition to the cost of the wall.

Sketch of a Ha-ha

Ha-ha

Garden walls

A sketch of a garden gate leading into a further part of the garden.The wall is one of the oldest manmade structures, and its use in gardens is as old as gardens themselves. The word comes from the West Saxon weall which in itself comes from the Latin vallum meaning a rampart and in the garden walls are used as a natural development of earth ramparts. Initially walls in gardens were to divide the gardens private space from the rest of reality, but over the centuries their roll has evolved.

It must have quickly become apparent that walls change the immediate environment around them; providing shade, shelter, warm and support. A wall facing the south will create an area of warmth immediately in front of it both by reflecting the suns warmth and by absorbing this heat and then gradually releasing it after the sun has gone down.  An east facing wall will heat up early in the day and then release its heat when it is in shade in the afternoon, where as a west facing one will heat up later in the day preventing the rapid and damaging thawing of delicate spring blossoms. A north facing wall on the other hand will be cool and shady demanding plants suited to those conditions.

What is often over looked though is the effect walls have on the moisture in soil immediately beside them. The porous nature of brickwork will tend to draw moisture from the soil against it.  A greater effect though will be from the tendency to prevent rain being blown onto the leeward side of the wall; making the side sheltered from the prevailing wind drier. This effect will be further exasperated by any over hanging coping and more so by the eves of a roof.

In addition walls have a psychological effect; changing the way we perceive the space they enclose and its relationship with what is beyond them. Their presence can create a sense of privacy and security to those on both sides of the wall. Even a low wall creates a strong dividing line between the parts it separates; allowing the areas within the garden to be compartmentalised according to their form and/or function. Thereby creating uniformity: stopping different styles and uses clashing; in forcing a sense of order.

A further layer is added to this relationship by the openings placed in walls. Large ornate gates form an imposing status symbol, framing and thereby controlling the view of the area with in. Small openings control both the access to the interior space and what can be seen of it creating a different sense of drama. This can be further manipulated by the choice of how this opening is filled. A solid door will block the view out of the walled area while creating a sense of mystery: while one that you can see through will entice the viewer though into the space beyond.

Each wave of garden design style has found new uses for walls, as the demands we place on gardens change and new materials to construct them from become available. Thus the role of the garden wall continues to develop with each generation of gardeners.

Drive design

With drives, probably more than any other thing in gardens, the most important thing is it actually functions as the drive. No mater how nice it may look if it does work as a drive it is a waste of money. As ever there has to be some compromises, you may what a turning circle in your drive but they need an awful lot of space. First you need to decide how many vehicles you are going to what to park on the drive and do you need to be able to pull onto the drive, turn around and then drive back out. You also need to consider the order the vehicles will be needed, ideally you are not going to want to be constantly moving vehicles around just to get one particular one out. Last but not least you need to consider access to garages and house doors and how much of your garden you what to make into the drive.

Sandstone block paving at Winchester

Sandstone block paving at Winchester

Now look at what space you’ve got. An average car needs a space of 2.4 metres by 4.8 metres to park on and this doesn’t include space for manoeuvring it. Make a sketch and some vehicle sized pieces of card and try moving them about on the sketch, allowing for how they are going to swing out when turning. At this point you are going to have to make some compromises so consider what is important. Once you feel comfortable with the layout of your drive mark it out in the garden as you plant to have it and actually try it out. It is far easier to change now than later.

Cobble drive

Cobble drive

You are almost ready to construct your drive but before you start checking the cost of materials it is important to consider if planning permission is needed. The pressure for off road parking has lead to more and more gardens being paved over and while this does get cars off the sides of roads it means the rain that would soak into the front gardens now runs off. In response to this the government decided to bring in planning controls to cover non-porous paving in front gardens. Further details can be found on the government’s planning portal here. Planning rules are complex and special rules can apply in many situations so a 5 minute phone call to you local planning office at this point can save a great deal of trouble later. What ever you do don’t try to emulate the Ostrich!

. Planning rules are complex and special rules can apply in many situations so a 5 minute phone call to you local planning office at this point can save a great deal of trouble later. What ever you do don’t try to emulate the Ostrich!

Paving materials

 

The trick when designing your patio is to make it blend into the surrounds while adding to them. To do this you are free to use every trick in the book. You can use materials which contrast with their surrounding or complement them but care should be taken when trying to match materials as a bad match can be the worst scenario. Nor should you restrict yourself to just one material as mixing in an additional material is a very good way to break up areas of paving and differentiation between different areas. Just don’t over do it!

Below I’ve put together a table of most of the paving/drive materials currently available, the list though is not exhaustive. The cost column is really only to give a very broad indication of the relative expense involved in using different ones The exact cost would depend on many factors including site conditions and how much if any of the work was undertaken on a DIY basis.

Paving Materials 

Material Cost Advantages Disadvantages
Bark Low
  • Low cost
  • Flexible
  • Soft
  • Water permeable
  • Tends to spread about
  • Needs edging
Gravel Low
  • Low cost
  • Flexible
  • Comes in a very wide variety of colours and shapes
  • Water permeable
  • Tends to move about
  • Needs edging
  • If to soft it will quickly disintegrate
  • Only suitable for level areas
Plain concrete flags Low to medium
  • Low cost
  • Readily available
  • Provides a smooth surface
  • Does not need pointing
  • Good under sheds and for utility areas
  • Visually unattractive
  • Very heavy
Coloured concrete flags Low to medium
  • Low Cost
  • Readily available
  • Provides a smooth surface
  • Do not need pointing
  • Visually unattractive
  • Very heavy
  • Colours fade – particularly reds
Buget riven flags Low to medium
  • Low cost
  • More attractive than plain flags
  • Do not need pointing
  • Not as attractive as the more expense flags
  • Limited range of colours and sizes
  • Poor finish
  • Limited range of patterns
Premium riven flags Medium
  • Very wide range to choose from
  • Large range of flags shapes and sizes
  • Can be as expensive as imported flags
  • Care needed to ensure they are laid with the correct fall
  • Limited life
Imported stone flags Medium
  • Almost limitless life
  • Very hard wearing
  • Cost is equivalent to/or less than premium manmade flags
  • Needs a diamond blade to cut them
  • Brittle so hard to work
Block paving Medium to high
  • Very wide range of colours and patterns
  • Very hard wearing
  • Small size makes them very flexible
  • Must be securely edged
  • Red ones fade
  • Large areas can look like parking even if its not
  • Cannot be cleaned by pressure washing
  • The surface must be 600mm above the watertable
Stone setts High
  • Hard to very hard wearing
  • Small size makes them very flexible
  • Difficult to lay
  • Need a very solid base
  • Expensive
  • Need to be pointed
New sandstone flags High
  • Almost limitless life
  • Natural product
  • Very attractive
  • Heavy
  • Expensive
  • Requires skill to be laid well
Reclaimed sandstone flags Very high
  • Almost limitless life
  • Laid well are very attractive
  • Particularly prone to becoming slippery
  • Very heavy
  • Very expensive
  • Require skill to lay them well
Mosaics High to very high
  • Can look very attractive
  • Unusual
  • Requires a lot of skill
Sandstone crazy paving Medium
  • Flexible
  • A cost effective alternative to sandstone flags
  • Needs skill to lay it well
  • Can be hard to source
Tarmac High
  • Makes an excellent hardwearing surface
  • Smooth
  • Flexible
  • Comes in a range of colours
  • Requires specialist skills to lay
  • Only practical if sufficiently large area
  • Must have a secure edging
  • Limited range of colours
  • Not very attractive
Cobble paving High
  • Can look very good in the correct setting
  • Hard to source good warn cobbles
  • Very uneven surface
  • Prone to being slippery
  • Requires a lot of skill to lay it well
Decking Medium
  • Can be laid in a range of patterns
  • Comes in a range of finishes
  • Very good for levelling sloping sites
  • Flexible
  • Prone to being slippery
  • Limited life
  • Requires more maintenance
  • Needs to be lifted off the ground
  • Any decking surface over 300mm above the ground level requires permission from your local authority
Concrete slab Medium
  • Smooth
  • Can be textured
  • Laid well it is very durable
  • Capable of supporting heavy loads
  • Very good for utility areas
  • Requires skill to lay
  • Large areas require good access
  • Difficult to make good if it is damaged
Pattern impressed concrete Medium
  • Visually much better than plain concrete
  • Is only a surface treatment so prone to surface damage
  • Very difficult to make good if damaged
  • The colour will wear away where car wheels repeatedly run over it
Brick High
  • Small units allow flexible designs
  • Small thier small sizes makes trhem good for small areas
  • Bricks must be carefully chosen because of the risk of frost damage
  • Skill required to lay
Reinforced grass Medium
  • Provides a visually “soft” appearance
  • Water permeable
  • Only really suitable for car parking or intensely used footpaths

Brick

A small regular building unit traditionally made from fired clay but occasionally concrete. They have been used for thousand of years in various sizes and still are available in a range of sizes; with different standard sizes in different countries. In addition to the normal cuboid shape bricks are also many  other shapes available for specific purposes and these are called “specials”.

Standard Uk brick with nominal dimensions
Standard UK brick with nominal dimensions