The complexity and laboriousness of erecting the formwork of the stairs directly depend on the form and its type.
The staircase, located between two walls, has the lightest design – no need to make side formwork. The walls themselves perform a load-bearing function. Frame elements are attached to them.
- The formwork for a single-flight staircase is easily and simply assembled. It is necessary to mount only one end formwork, as well as stair supports.
- More complex formwork will require the construction of a staircase with several flights and platforms between them. For additional details, you will need various formwork elements, columns, and supports.
- A spiral concrete staircase has the most complex formwork. The formwork consists of numerous curvilinear parts and many supports. It is tough to manufacture, time-consuming and requires serious financial investments.
The reliability, longevity, and beauty of the future concrete staircase depend on the correct assembly and strength of the formwork.
Edged board and waterproof plywood are the main formwork elements.
When installing props, it is necessary to consider the large weight of concrete. Racks of assembled formwork should stand on the soil or floor and not hang in the air before pouring concrete. To avoid this, you can put linings under them or drive in wedges. The whole structure is interconnected by boards – this increases its rigidity.
The last stage of formwork assembly is reinforcement. This will give strength and rigidity to the entire structure. Ribbed reinforcement is usually used, with a wire diameter of 10 to 12 mm. Reinforcement elements are interconnected by soft wire.
The concreting of the stairs is done at a time. Filling begins with the lower steps. Crushed stone is added to the concrete so that it does not flow out of the formwork. Be sure to use an electric vibrator. This will compact the concrete and prevent the formation of air cavities. After drying, the formwork is dismantled, and the stairs are decorated with railings and various decorative materials.