A garden composed of different levels will look disjointed unless there is some visual link between parts. A flight of steps not only serves the practical purpose of providing access to the various levels but also gives a co-ordinated look to a scheme.
The main purpose of steps is to provide access from one level to another and they’re an important factor in the landscaping of a garden, bringing otherwise detached areas into the overall scheme. Wide, shallow steps can. For example, double as seating for a terrace bordering a lawn, or as a display area for plants in containers, while narrow, angular steps will accentuate interesting changes of ground level.
Types of materials
For a good visual effect, the steps should be constructed from materials that complement the style of the garden. If you’ve built a path, for instance, continue the run by using the same materials for the steps. Where you’re building up to a wall, match the two structures, again by using the same materials.
For a formal flight, bricks can be used as risers (the vertical height of the step) Decorative walling blocks with ‘riven’ or split faces, or natural stone, used in the same way give a softer, more countrified look. You can top these materials with either smooth- or riven-faced slabs or even quarry tiles to form the treads (the horizontal part of the step on which you walk) Or, if you prefer, you can use other combinations of building materials for the steps, bricks and blocks, for example. Make attractive treads as well as risers.
You can choose from a wide range of coloured bricks, blocks and slabs, mixing and matching them to best effect. Pre-cast or cast in situ concrete can be used as a firm base for these materials or makes a durable surface in its own right.
Planning the steps
There are no building regulations governing the construction of garden steps so you have a lot of flexibility in deciding how they will look. Sketch out possible routes – you can build them parallel to the side of the terrace so they don’t extend loo far into the garden This is particularly suitable where the ground slope is steep. Decide whether the steps will be flanked by flower beds, rockeries or lawn, or linked at the sides to existing or new walls You could build steps with double-skinned side walls and fill the gap between with soil to use as a planter
Bear in mind the dimensions of the completed steps when choosing materials Treads and risers should measure the same throughout the flight to ensure a constant, safe, walking rhythm (If they are not constant the variations must be made visually obvious for safety reasons.) Make provision, also, for drainage of rainwater from the steps by sloping the treads slightly towards the front.
Steps should be neither too steep nor too gradual – steepness can cause strain and loss of balance while with too shallow a climb you run the danger of tripping on the steps. Steep steps, and those likely to be used by children and elderly people, require railings on one or both sides to aid balance. These can be of either tubular metal or wood and should be set at a height where your hand can rest on top comfortably – this usually works out at about 850mm (2ft 9in) high measured from the nose of the steps. Alternatively, you can build small brick, block or stone walls at each side of the flight. There should be no hand obstructions along the length of the railings or walls, or other projections on which clothing could snag. Railings should also extend beyond both ends of the flight by about 300mm (1 ft); they might, in fact, continue an existing run of railings along a path.
Treads should be non-slip for safety. However, this is difficult to achieve outdoors, where they are subjected to ice, rain r and formation of moss. Proprietary liquids are available for painting on treads so they won’t be slippery but a more practical solution is to use hydraulically-pressed slabs, which come with a variety of surface textures or relief designs that are both attractive and non-slip.
When you’ve decided on the basic appearance and route of the steps you must calculate the quantity of bricks, slabs or other material you’ll need. It’s best to work out your design taking into account the sizes of slabs, blocks or bricks available. Make a scale plan (bird’s eye view) and a side view on graph paper to help in planning and construction.
In order to support the steps, concrete trench foundations must be formed underneath the retaining walls. Mark out these foundations using strings stretched between pegs. Con-struct the flight one stepat a time. When the first courses of the retaining walls have been built, a hardcore filling is used to provide a firm base for the treads. When this is rammed down, lay a blinding layer of sharp sand to fill gaps and provide a level bed for the treads. Subsequent levels are built on top in the same way and the treads laid on mortar.
When tamping down the hardcore back-filling in each level take care not to dislodge any bricks or blocks. Concentrate on the areas that will support the next risers and the back edges of the treads because these parts are subject to the most pressure.
This method of construction is suitable only for freestanding units up to five steps high. If you want larger steps, you’ll have to make substantial foundations in the form of a cast concrete slab about 75mm (3in) thick, covering the entire area of the steps, and build intermediate supporting walls the width of the flight under each riser – a hardcore back-filling alone is simply not firm enough to support the extra weight. These walls can be laid in a honeycomb fashion, with gaps between the bricks in each course; this allows for drainage through the structure and uses less bricks than a solid wall. Each section formed by the intermediate walls should contain a rammed-down hardcore back-filling topped with a blinding layer of sand.
Alternatively, you can cast a solid concrete flight in timber formwork and lay the surface materials on top, bedded in mortar, but this will involve large quantities of concrete.
Larger flights built up to a wall should be joined to the wall or there’s the risk of them parting company after time. Tooth-in’ alternate courses to the brickwork or block-work of the terrace by removing a brick from the terrace wall and slotting in the last whole brick from the side walls of the steps. On smaller flights you can tie in the steps by bedding a large 6in (150mm) nail in a mortar joint between the two structures for added rigidity.
To ensure comfortable, safe walking, garden steps must be uniform in size throughout the flight, and neither too steep nor too shallow.
Risers are usually between 100mm and 175mm (4in and 7in) high. The shallower the slope the shallower the risers. Treads should not be less than 300mm (1 ft) deep – enough to take the ball of the foot on descending without the back of the leg hitting the step above. They should be about 600mm (2ft) wide for one person; 1.5m (5ft) for two people. Nosing is the front of the tread, which projects beyond the riser by about 25mm (1 in) to accentuate the line of the step in shadow.
HOW MANY STEPS?
To calculate the number of steps:.
– measure the vertical distance between the two levels
– divide the height of a single riser (including the tread thickness where relevant) into the vertical height to determine the number of risers.
TYPICAL TREAD/RISER COMBINATIONS
For comfortable walking combine deep treads with low risers, shallower treads with high risers.
Tread Riser 450mm (1ft 5V:>in) 110mm (4 V2in) 430mm (1 ft 5in) 125mm(5in) 400mm (1 ft 4in) 140mm (5 ‘/an) 380mm (1ft3in) 150mm (6in) 330mm (1 ft 1 in) 165mm (61/2in)
Bed treads and risers in a fairly stiff mortar mix: 1 part cement to 5 parts sand.
HOW MUCH MORTAR? 50kg cement mixed with 24 two gallon (9 litre) buckets of damp sand will be sufficient to lay about 7sq m of slabs -around 35 slabs 450 x 450mm (18 x 18in) – on a 25mm (1 in) thick bed. Don’t mix this much mortar at once or it will set before you can use it all.
The type of brick bond you use in the con-struction of the retaining walls depends upon the size of the materials you use for the risers. You should, though, try to keep the perpends consistent throughout the flight for strength and for best visual effect.
It’s wise to dry-lay bricks or blocks first to make sure you get the best – and strongest -bond; perpends that are very close together mean a weaker construction and you should try to avoid this if possible. When choosing materials, you should take note of typical, ‘safe’, tread/ riser combinations deep and twice as wide as each retaining wall
– broken brick or concrete back-filling
A flight larger than five treads requires:.
– substantial foundations in the form of a cast concrete slab about 75mm (3in) thick, covering the entire area of the steps.
– intermediate supporting walls the width of the flight under each riser
– rammed-down hardcore back-filling topped with a blinding layer of sand
– or a concrete base flight cast in timber formwork, on which the surface materials can be laid, bedded in mortar.
Rainwater must not be allowed to collect on the steps. Provide drainage by:
– allowing for a fall of about 12mm (1/2in) to the front of each tread or, where the steps abut a wall:
– make concrete gullies about 50mm (2in) deep by 75mm (3in) wide at each side of the flight to drain from the top.
If the flight drains towards a house wall:
• make a channel at the foot of the steps, parallel to the wall, to divert water to a suitable drainage point.