A stairs in a house or building construction designed to cover vertical distance by providing set of steps. Stair have many components i.e. steps, risers, flight, landing, railing etc. At the time of designing/constructing stairs, there are many things to consider by the house owner, which provide easy and quick access to different floors. According to shape, stairs may be straight, circular, spiral and curved etc. According to materials, stairs built of stone, reinforced concrete, timber and steel. Due to shortage of good quality timber and with scarcity of stone, reinforced cement concrete stairs are mostly in use in residential and commercial buildings. Steel stairs commonly used in thermal power stations, industrial plants, warehouse etc.
For a comfortable stair design some points should be consider which are as follow.
Width of stairs
Keep the width of stairs as per the situation and use of stairs. According to the norms, the minimum width of stairs should be 0.75 meter. For row of housing with two stories the minimum width, require 1-00 meter. For hotels, education buildings, offices, theaters etc width should not be less than 1.5 meter. For institutional building, hospital, shopping complex the width should be 2-00 meter.
Slope of Stairs
At the time of constructing stairs, the slope should not be steep. The ideal slope is 30-degree for comfortable use of stairs but in case due to shortage of space, the slope should not exceed 45 degree.
Width of tread
Height of risers
For comfortable use of the stairs, the height of riser should not be more than 190 mm for residential building and it should be 150 to 160 mm for non-residential building. Due to shortage of space, the height of riser may be kept 200mm but it cause difficulty to old age and children. To avoid any mishap the size of riser should be same.
Note;- The vertical distance between two steps is termed as riser or it is describe as the vertical distance from the surface of one step to the next step.
Unequal size of steps
Make sure that the all risers are of consistent height from the top to bottom otherwise it may cause accident. Risers of different height will throw the cadence of foot that may cause fall in stairs.
Floor is an important feature of safe and easily accessible stairs. Non slippery material should be used for stairs floor. If the floor of stair steps slippery, then it may cause accident and some time it may be fatal. Marble floor is best suitable for residence; avoid polishing of marble that will make the marble slippery. Chequered tile flooring is best suitable for steps of stairs in public place where stair is open to rain as in railway over bridges at platform etc.
Provision of Hand Rail at proper height
Handrail must be provided in the stairs for comfortable use of stairs. Make sure that hand rails are easily seen in day or night time. Where both end of stair is open provide the handrail on both sides of stairs. In case where stair has walls on both sides then handrail should be provided on walls. The height of handrail should not be less than 800mm and not more than 900mm. The space between the supports of handrail in houses should not more than 250mm and horizontal/ cross support should be 150 mm from top of stair steps to avoid any accidental fall especially for kids.
Make sure there is proper arrangement of light other wise it may cause accident in night. 2-way electric switches should be used for stairs for easy access of switch from top and bottom of the stairs. Provision of natural light and ventilation is necessary in the stair to save energy bill during day time and stair can be used at the time of electricity failure. Due to proper ventilation, suffocation problem also not arises.
Provision of gates
Some times it has been seen that baby / kids climb on the steps and are not able to return then they either cry for help or fell in the steps. To avoid such situation proper gates/ doors must be provide at the top and bottom of stair with locking arrangements. It is also necessary for security to avoid the entry of intruders.
The clear height above stair steps is called headroom. If headroom is less than 170 cm, than there is a chances of accident. In this situation when a person going upward there is less chance of accident but in down ward direction there are more chances of accident to strike head on beam of landing/ flight of stair. In unavoidable situation, a caution is to be given by printing “mind your head”. For easy movement of furniture in stairs, the minimum clear headroom in stairs should be 2.00 meters.
The maximum numbers of steps should not be more than 15 in one flight if so landing should be provided after 15 steps for comfort while moving up and down the stairs. Avoid water tap near the entry of stairs on terrace if so there are chances of water flow in the stairs that will make the stairs slippery.