10 DIFFERENT TYPES OF STAIRS COMMONLY DESIGNED FOR BUILDINGS

TYPES OF STAIRS

A stair is a series of steps arranged in such a manner as to connect different floors of a building. Stairs are designed to provide as easy and quick access to different floors. A staircase is an enclosure which contains the complete stairway.

Generally stairs are of following types

1. Straight stairs
2. Quarter turn stairs
3. Half turn stairs
4. Three quarter turn stairs
5. Circular stairs
6. Spiral stairs
7. Curved stairs
8. Geometric stairs
9. Bifurcated stairs and
10. Combination above types

1. STRAIGHT STAIRS

These are the stairs along which there is no change in direction on any flight between two successive floors. The straight stairs can be of following types.

• Straight run with a single flight between floors
• Straight run with a series of flight without change in direction
• Parallel stairs
• Angle stairs
• Scissors stairs

Straight stairs can have a change in direction at an intermediate landing. In case of angle stairs, the successive flights are at an angle to each other. Scissor stairs are comprised of a pair of straight runs in opposite directions and are placed on opposite sides of a fire resistive wall.

Straight Stair with Single Flight

Straight Stair with Two Flights

2. QUARTER TURN STAIRS

They are provided when the direction of flight is to be changed by 900. The change in direction can be effected by either introducing a quarter space landing or by providing winders at the junctions.

Quarter Turn Stairs

3. HALF TURN STAIRS

These stairs change their direction through 1800. It can be either dog-legged or open newel type. In case of dog legged stairs the flights are in opposite directions and no space is provided between the flights in plan. On the other hand in open newel stairs, there is a well or opening between the flights and it may be used to accommodate a lift. These stairs are used at places where sufficient space is available.

Half turn stair

Half Turn Stairs

4. THREE QUARTER TURN STAIRS

These types of stairs change their directions through 2700. In other words direction is changed three times with its upper flight crossing the bottom one. In this type of construction an open well is formed.

5. CIRCULAR STAIRS

These stairs, when viewed from above, appear to follow circle with a single centre of curvature and large radius. These stairs are generally provided at the rear of a building to give access for servicing at various floors. All the steps radiate from a newel post in the form of winders. These stairs can be constructed in stone, cast iron or R.C.C.

Spiral Stairs

6. SPIRAL STAIRS

These stairs are similar to circular stairs except that the radius of curvature is small and the stairs may be supported by a center post. Overall diameter of such stairs may range from 1 to 2.5 m.

7. CURVED STAIRS

These stairs, when viewed from above, appear to follow a curve with two or more centre of curvature, such as ellipse.

8. GEOMETRICAL STAIRS

Half turn Geometrical Stair

These stairs have no newel post and are of any geometrical shape. The change in direction in these stairs is achieved through winders. The stairs require more skill for its construction and are weaker than open newel stairs. In these stairs the open well between the forward and the backward flights is curved.

9. BIFURCATED STAIRS

These stairs are so arranged that there is a wide flight at the start which is subdivided into narrow flights at the mid-landing. The two narrow flights start from either side of mid landing. Generally these stairs are more suitable for modern public buildings.

Bifurcated Stairs

10. COMBINATION OF DIFFERENT TYPES

Depending upon the requirement of a building or as per owner’s demand few of the types as mentioned above can be combined to design a new stair.

AN INSIGHT TO CONCRETE RAMPS FOR BUILDINGS

concrete ramps

Ramps are of great importance in any high-rise building. Ramps provide safe access to the building for heavy materials such as heavy machineries. In many countries the construction of a ramp in a building is made compulsory by law abiding bodies to provide safe and convenient access to people with disabilities as by the help of ramps carrying people on wheel chair is much more convenient.  While it provides a multitude array of benefits as ramps are useful for strollers, wheelchairs, and any moving device with wheels, it may sometimes cumbersome and looks irrelevant with the design of the building that cause challenges for the architectures.

There are different principles of constructing a ramp, but for a very long period of time one of the most durable, is the concrete ramp.  Due to the toughness of concrete it provides strong cohesion that supports heavy materials load and provides a surface that controls traction and maintains grip for the wheels to move over.

When it comes to high rise building and other skyscrapers the role of a concrete ramp is of great assistance. A concrete ramp can offer comprehensive solution for moving heavy materials in and out of the building and creating assistance for disable people to get their wheelchairs in or out. The mechanism for constructing a ramp may sound very simple but it is surely the most effective.

The construction process is based on the principle of pouring concrete in the mold which is ramp shaped. The mold takes the shape of a slab that is used to create ramps. A wooden frame is made and kept over compacted gravel. The wooden frame is filled up to the top level and then removed after drying. Pieces of plywood are used to cut an angle along the top of the frame those results in slop construction.

One of the most crucial factors of concrete shaping is the use of a stiff mixture. The perfect proportion of water in concrete is very crucial. Is the water level gets high the concrete will slump down and makes the surface uneven. Best Practices is to flatten the form while filling and pouring into the mold. It minimizes the chance of slumping and provides an even texture and uniformity. Flattening the concrete by the help of a float in a bottom up direction reduces granules to form making the concrete uneven. The amount of concrete and water in the mixture may vary according to the length of the concrete. The length of the ramp is based on the requirements, longer the length of the slope the more gently it is. Ramp that are designed for disable people and are made with non-slip, traction control characteristic for easy, safe and convenient movement of wheel chair.

 THE CONSTRUCTION PROCESS

THE SUB-BASE OF THE RAMP

The sub-base is the most important building block of ramp. It supports the entire load and hence it should be strong enough to support the overall weight of the ramp. If your ramp is consuming 4 inches of compacted gravel the appropriate proportion will be ¾ Inch of plywood and 2 x4 lumber. It is important that the side pieces are identical and applied to the same level with each other.

BRACING THE FORM

Make sure that the level remains identical. If any of the ramp walkways meet with any slab, or other structures. It very important to isolate it by a wooden piece that acts as a juncture.

ADEQUATE MIXING OF THE CONCRETE

The concrete should be mixed with proper amount of water. IT should not be dry or wet more than the recommended level.  Fill the form in the mold and by the help of a float spread the mixture evenly. By the help of shovel settle the concrete to avoid any slumping.

A GENTLE ROUNDING OF THE EDGES

The best looking ramp is one that has smooth edges. By the help of a edger smoothen and brooms the edges of the ramps making it non-slippery. To make the ramp strong moist cure it for at least a week, the wooden form can be removed after 4 days.

SOME IMPORTANT FACTORS

SLOPE

Slope is the backbone of any ramp. A ramp can only be accessible by the help of slope. The optimum ratio of the slope with the ground should be 1:20; this representation shows that the slope should be inclined one inch for every twenty inches of a flat surface to provide maximum convenience.

THE DIMENSIONS

The length of the ramp should be long enough to provide gentle movement and the width should be enough to easily accommodate moving objects.  The minimum width for a small ramp is 36 inches inside the handrails. The optimum width for a ramp is 48 inches.

LANDINGS

An ideal ramp should have an identical ramp inclination at both the sides. Every opening and closing door of a ramp should also have a landing. These landings are of great importance to maintain balance while opening doors and manipulating materials.

HANDRAILS

When it comes to support and safety handrails provides safety barriers to the user of the ramp. Moreover it serves as a balancing aide and offers means of propulsion for wheel chairs that are manual.  For maximum support handrails should be smooth and continuous. Handrails should be provided on both side of the ramp to facilitate many users at one time.

EDGE FINISHING

It is very important for ramp to get it edges finished. Edge protection is also commonly known as crutch stop that allows safety of people against getting of the ramp. The optimum edge protection of the ramp should be minimum four inches.

Author name:

Jason Root.

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Source:- www.civilblog.org