- What to do
- Good seating
- Staircase in railway sleepers
- How to do:
- A staircase of brick and wood...
- A mineral staircase
Indispensable when the ground is sloping or has several levels, the staircase must be above all passable. It is built in harmony with nature.
Transitional space, the garden stairs must lead the walker to the front door, the terrace or the pool without excessive fatigue and safely. As for its integration into the environment, you will find a wide choice of locations and materials (stone, tile, brick, logs or railway ties...).
What to do
Often less important in elevation than an interior model, the garden staircase can be designed taking a few liberties with the rules of construction and sizing steps. Sketches illustrating the different implementation possibilities are strongly recommended.
The number of steps and their dimensions are determined by the size of the stairs (the difference in level between the bottom of the first step and the top of the last step). In a garden, the height of a walk is between 12 to 15 cm (15 cm being the limit not to be exceeded). This height must remain constant to avoid missteps!
The walking depth (the tread) is determined by the length of the future staircase. The more space the foot has to land, the more comfortable the staircase is to climb and secure. In a garden, favor a lap of 35-40 cm to stop on the way without risk of falling. It must have a slight gradient of about 1 cm / m to evacuate rainwater.
The width of the staircase (step) is between 100 and 150 cm to allow two people to borrow or "cross". Larger, it will be much more difficult to integrate into the vegetation.
The construction of a garden staircase is done in different ways. The most classic is the laying of a coating on a concrete base. It is a solid, stable and resistant to earth surges. Concrete can receive any type of flooring: stoneware or terracotta tiles, natural or reconstituted stone paving...
The depth of the earthworks is dependent on the thickness of the concrete (or any other material) and that of the coating. For a classic structure that does not have to withstand enormous constraints (frequent passages, large field surges...), it takes 10 cm for the seat.
First, demarcate the staircase by tracing its location on the floor (for example by laying a bead of plaster). Plan a little wider to anchor the seat in the ground. The surplus will be concealed by an embankment or a curb... Dig with the spade to reach the required depth.
From the bottom, materialize on stakes driven into the ground the upper edge (and the tread consequently) of each step of the seat. Do not forget to subtract the thickness of the coating. Arrange a reinforcement to arm the concrete.
Realize the formwork of the steps with planks leveled, wedged and blocked at their ends in the ground or nailed to the stakes driven into the ground. In the formwork, pour a concrete dosed at 350 kg / m3, starting from the top. Smooth the concrete horizontally to the ruler or trowel to create the tread of the steps by taking the top edge of each plank as a marker.
Staircase in railway sleepers
Placed horizontally, railway sleepers are bordered by other vertical sleepers. Their very important weight allows an implementation on a bed of groomed sand.
How to do:
Cords materialize the edges of the staircase. A thick bed of sand is spread over the earthworks. The upper step adjusts to the same level as the terrace.
The penultimate step consists of a row of gravelled concrete slabs, blocked by a crossbar serving as a stair nosing. To lay the following ones, dig the ground on a thickness equal to the height of the future step. Level the sand with the rake, then lady before wedging the crossbar against the base of the previous one and against the previously half-buried border bars.
Check the horizontality as you set it up.
A staircase of brick and wood...
The elevation of the slope of the garden has led to landings. These not only make the practice of this imposing staircase more comfortable, offering the possibility to mark stops to admire the vegetation, but they also allow it to rotate smoothly.
Rustic and warm, the bricks that cover the landings and the steps have been chosen with care. They are fired at more than 1000° C, which reduces their porosity, improves their resistance to wear and frost. They are sealed on a reinforced concrete base, with a bastard mortar (1 volume - 2/3 cement CEM II 42,5 R, 1/3 lime NHL 3,5 - for 4 of sand).
The bricks are moistened before laying until saturation (soaking for several hours). It is imperative to give the bearings and steps a slight slope so that it evacuates the rainwater (and watering). If they stagnate, they represent a potential danger for walkers. They also compromise the cohesion of the building by infiltrating the masonry. By freezing winter, they put significant pressure on the steps and landings that may collapse.
Unearthed in a material recovery (or directly to the SNCF), railway sleepers that line the stairs and hold the land exist in different lengths. Their strong section (20 to 26 x 12 to 15 cm) and the treatments they have undergone give them an exceptional longevity but seem today to pose environmental problems (risk of pollution of the ground). They are placed side by side, vertically. Their base is then buried one-third of their height or sealed at least 30 cm deep in a bed of reinforced concrete. Their vertices are aligned to achieve successive flights of different heights. Before backfilling, a geotextile film is stapled to prevent the infiltration of the earth between the sleepers.
A mineral staircase
Very simple in its design, but perfectly integrated in the environment of the garden, this staircase mixes pavers and gravels. The absence of a reinforced concrete seat along the entire length of the staircase is made possible by the perfectly stable natural floor.
The earthworks requires the materialization of the edge of each step by cords stretched between stakes to dig first the outline of the stairs. It is then necessary to reposition the cords at the exact height of each step (that of the paving stones in this case) and to search if necessary before compacting the ground.
Behind each cord, dig a trench 15-20 cm deep about 10-15 cm across the entire width of the step. Concrete is poured on an armature to make a foundation footing. The sandstone blocks which act as risers are sealed above with cement mortar.
The gravel chosen is a crushed river gravel, more pleasant to walk than crushed gravel. It spreads on a thickness of 7 to 10 cm. A geotextile film (a garden felt) is interposed to facilitate drainage, avoid gravel migration into the soil and weed growth.