Concrete Stairs: How to Construct it
Several steps are involved in construction of concrete stairs. They are designing, preparing foundation, building form work, placing reinforced steel bars, concreting, finishing and curing. It is a difficult task, and engineers need to study all aspects before designing it. Then, skilled labour is needed to construct it..
Steps involved in construction of concrete stairs.
1. Designing of stairs: First thorough knowledge of design aspects and site study is needed. Factors influencing the design of stairs are, height of the floor, width of the stairs, risers depth, thread width, thickness of the stairs, angle of the stairs, load applied on the stairs etc. These require a qualified engineer to design the stairs perfectly.
2. Foundation and support for concrete stairs: Even concrete stairs need foundation to rest on properly. This is needed for the load of the stair to be successfully transferred in to the ground, thus resisting the movement of stairs.
If plinth beam of building is present at the stairs, then the reinforcement steel bars can be connected with them. If that is not possible, small concrete foundation or size stone masonry is constructed.
3. Building form-work: This is the most important step. The angle of flight, dimensions of thread and riser are to be checked properly. Usually while constructing stairs attached to a wall, the line of flight, thread and risers are properly marked. The boards must be 2” thick to support the weight of the concrete.
4. Steel reinforcement: Steel bar reinforcement is done to transfer the load to the ground. The number and size of steel bars is to be calculated depending on the load.
5. Pouring of concrete: Concrete is to be poured into the framework form below to above. It is recommended to use concrete vibrator while pouring concrete to completely fill the gaps of the stairs.
6. Removal of formwork: At least 21 days is required for the concrete to dry properly. After that, the formwork is to be removed with a hammer and a crowbar.
7. Finishing of the stairs: The stairs may be finished in several ways depending on the requirements. It can be finished using trowel or float, cement tiles, granite, etc.