Staircases are often the first thing people see when they enter a building. Stairs can be used to connect one floor to another, or provide access to levels that are not on the same level. Stairs should always meet certain requirements and follow guidelines before installation. Staircases types can range from spiral staircases for tight spaces, straight flights of stairs with landings in between floors, or even grand sweeping stairways with long winding curves.
– Staircase Requirements
While there is no standard set of rules for all staircases, there are some general requirements that should be met before installing them anywhere. The primary requirement is safety; any staircase must have a railing on both sides and include at least one landing per flight where someone could turn around. Stairs should always be installed in pairs with matching handrails and balusters (baluster is the vertical metal bar). These guidelines are for normal buildings, but there are also regulations that apply to other areas such as mobile homes, ships or trains.
A good staircase should be provided for quick and safe communication from one floor to another. There are particular requirements of a stair as given below:
The treads of the stairs should be firm on the landing so that they do not sag or give way under weight, especially on first floor where maximum number of people come to use the stairs. The first floor side of the treads should be slightly narrower than that on other flooes to avoid people tripping.
The risers should not be too high or too low. The rise should preferably be uniform throughout the stairs to avoid unnecessary climbing back and forth. It should also not tilt upwards at the ends, for this causes inconvenience in walking.
Preferably the steps should be of equal height for comfort in walking, but where height is very limited, it can be used in alternate short and long steps.
If the staircase has one riser more than another, innumerable accidents occur when people trip on them or they fall down because of their poor eyesight.
Therefore, the risers should be uniform throughout the whole staircase.
There are generally two kinds of stairs – straight and curved. According to its function straight stair is used for communication from one floor to another floor where as curved stair is used for communication between different wings of a building or levels of a same wing. The advantage of having curved stairs is that they not only give a pleasing appearance to the building, but also help in saving space and cost of construction.
The main requirement of curved stairs is that it should be provided with continuous hand-rail on the inside curve and on both sides for safety purpose. The treads and risers of curved stairs should be uniform as those of straight stairs.
Various materials are used for stair construction, the main of which is wood. Wood has been a popular material in terms of cost and durability. The disadvantage of wood is that it is fire prone and hard to fix with alloys or concrete. In modern buildings steel staircases have become most preferred due to its light weight, easy installation, and resistance to fire.
Treads of the stairs should be firm on the landing so that they do not sag or give way under weight, especially on first floor where maximum number of people come to use the stairs. The first floor side of the treads should be slightly narrower than that on other flooes to avoid people tripping.
– Staircases Guidelines
The three main types of stairs used include straight flight stairs, spiral staircases and winding curved flights. Stairs should be designed to allow people of all heights the ability to safely use them; this means that no step can be taller than eight inches or less than nine inches in height for a total rise per step of seven-and-a-half inches with a tread (the horizontal part of the step) of ten inches. Stairs should also be designed with a minimum width of 36-inches for one way traffic, and 42-inches if two people are walking side by side on it.
Stairs should not exceed a rise of 12-inches and the run between them cannot be more than 180 inches. Staircases can be made from wood, metal or concrete; each has its own set of guidelines to follow. Wood stairs should have at least two stringers (horizontal beams) spaced approximately one foot apart for every three feet in the rise. Stair treads should be at least 11-inches in depth, and not more than seven inches of the total stair width may be taken up by nosing (convex edge) for a maximum riser height of eight inches. Metal stairs are often used in industrial applications since they can support heavy loads without sag or deflection. Stairs are typically made from steel, aluminum or stainless steel. Stainless steel is the most durable material for stairs, but it may be more expensive than some other materials so some people opt to use aluminum instead. Staircases must have at least one handrail on both sides of the staircase and gating around stairwell openings in buildings where children are present. Stairs built on ships, trains and cars must follow special guidelines set by the American Society of Mechanical Engineers (ASME).
Height or Rise of Staircase
Height or rise of a staircase is an important measurement for determining the location and placing of landing. It should be noted that the total height, including the stringers (balusters) should not be included in overall height.
Please note that there are generally accepted industry standards for steps made out of wood, metal, cement etc., however due to possible variances in materials, the overall height of a staircase should be measured.
The following are industry standards for building stairs using normal building materials. Stair case rise is determined by the type and size of stair riser and tread, however depending on usage and preferences it may vary slightly:
– Staircase with open stringers (no supports) made of solid wood: Staircase rise or height should not exceed 7.9 inches (2 cm), while the run or width between stringers for a staircase with an open stringer should be 10.5 inches (26 cm).
– Staircase with closed stringers made of hardwood: Staircases constructed using closed stringers should not exceed 7.25 inches (18 cm) in width and 9.5 inches (24 cm) of rise.
– Staircase with open stringers made of hardwood: Staircase with an open stringer should be 10.5 inches (26 cm) wide with a maximum rise of 8.75 inches (22 cm).
– Staircase with closed stringers made of softwood or plywood: Staircases using closed stringers should not exceed 7.25 inches (18 cm) in width and 9.5 inches (24 cm) of rise, however there is no industry standard for staircases with open stringers. Staircases with open