Materials for Garden Walls
Boundary walls may be constructed from a wide range of materials including brick, stone and, for low walls, concrete walling blocks. Screen block walls (in which a pattern is cut through the blocks, allowing partial visibility) are a decorative and practical alternative to solid walls and are also suitable for dividing off parts of the garden. Walls may also be built using a combination of materials, such as brick with facing panels of flint.
When buying any building material, always check with the supplier that it is suitable for garden walls: it should be able to withstand moisture penetration from both sides and be frost-proof.
Large, plain walls may be painted with a masonry paint. If white (or another pale colour) is used on the garden side, this will reflect the light and contrast well with wall shrubs or other plants.
The Pros and Cons of Walls
Pros
* Long lasting
* Visually attractive
* Provide privacy and shelter
* Reduce noise and pollution
* Link house and garden
Cons
* Most expensive boundary
* Can be complicated to build
* Some materials difficult to obtain
Brick
Brick is the most widely available and most popular choice walling material, although concrete blocks manufactured to imitate natural clay bricks may also be used. Brick walls can make the perfect link between house and garden, but you must take care to match the bricks as closely as possible - brick can have a strong local character, and colours may vary. The best way of matching the brickwork of existing buildings is often achieved by buying used bricks, which are available in many styles and colours.
For garden walls, a 'facing' brick (a high quality brick which has an appealing look used for external walls) is often the best choice, but in some situations, such as in a modern architectural setting, a crisp 'engineering' brick with a glazed or semi-glazed surface may be more effective. A good builders' merchant or brick manufacturer will be able to show you sample walls which will give you a far better idea of the final visual effect than bricks in isolation.
Stone
Stone usually comes in uneven sizes, and so provides a more informal walling material than brick, and if it has been quarried in your area, will generally suit the surroundings. Stone walls can be either coursed, using similar sizes of stones, or random, in which stones of any size are used.
Traditionally, stone is laid dry with no mortar between the joints; this is a highly skilled job. A true dry stone wall is built so that the sides slope in slightly ('battered') towards the top. Dry stone walling has the additional advantage of allowing plants to be planted in the crevices or self-seed.
Mortar can also be used successfully in stone, preferably mixed with stone dust from the same quarry; however, you must ensure that the joints are regular and not too wide. Avoid putting too much mortar in the joints so that it squashes out between the stones.
Coping for stone walls usually comprises of stone set on edge, giving an uneven top. However, if the top of the wall is 450 mm (18 in) wide, a double course of bull-nosed brick can be used, which sets a crisp top in contrast to the informality below.
Concrete
Concrete often has a poor reputation as a building material, particularly in the UK, where it is seldom used to its full potential. In North America it is acknowledged as a low cost, durable, flexible and elegant landscaping material.
Concrete can be used either in block form, where it is laid in a similar way to bricks, or cast in place, when reinforced wet concrete is poured into a mould.
Concrete blocks usually measure 225 x 225 x 450 mm (9 x 9 x 18 in), and are very easy to use. They come with 'fair' (virtually smooth) faces or with rough faces suitable for subsequent rendering.
Rendered blocks look good alongside a contemporary building, and are ideal in conjunction with a house that has a rendered finish. Render can also be painted to extend a colour scheme into the garden. Fair-faced blocks are smooth enough to be used without rendering, and if carefully laid, with crisp joints slightly raked back, they may not need painting at all.
Geometric patterned screen blocks are usually available in white or cream, measuring approximately 300 x 300 mm (12 x 12 in). They are designed to create a partially open boundary though which the view beyond may be seen. However, their busy pattern and somewhat harsh colour are not to everyone's taste. Simple block patterns are available, and the overall effect may be softened with the well thought out use of climbers.
Cast concrete walls can be very attractive, but their construction will probably require professional help. Wooden shuttering must be erected to contain the poured concrete, and reinforcing rods bedded into the foundations. The bottom of the wall must be wider than the top, and a 'toe' can be cast at the front, to act as a lever against pressure from behind.