Types of Staircase
- The stairs may be built with wood, concrete masonry, or cast iron.
- Wooden stairs are not safe because of the danger of fire.
- But they’re used in unimportant buildings to access small areas on the upper floors.
- Cast iron or steel stairs into the spiral forms were used generally to reduce the staircase area.
- In many residential buildings, masonry stairs are also used.
- Reinforced concrete stairs are very generally used in all types of buildings.
Based on the shapes stairs may be classified as(Staircase Types) :
- Straight Stairs
- Dog Legged Stairs
- Well or Open-Newel Stairs
- Geometrical Stairs
- Spiral Stairs
- Bifurcated stairs
- Turning Stairs
- Circular Stair
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#1. Straight Stairs
- If the space available for the staircase is long and narrow, straight stairs may be provided.
- Such stairs are generally used to give access to a porch or as emergency exits to cinema halls.
- All steps are in one direction. They may be provided in a single flight or in two flights with a landing between the two flights as below fig.
#2. Dog Legged Stairs
- It consists of two straight flights with a 180° turn between the two. They are very gently used to give access from floor to floor. as per below fig. shows this arrangement of steps in such stairs.
#3. Well Newel Stairs
- Well Newel Stairs also know Open-Newel Stairs
- It differs from dog legged stairs such as that in this case, there are 0.15 m to 1.0 m gaps between the two adjacent flights. As per below fig. shows a typical open newel stair.
#4. Geometrical Stair
- This types of stair is the same as to the open newel stair except that well-formed between the two adjacent flights is curved. The handrail provided is continuous.
#5. Spiral Stairs
- These stairs are generally used as per emergency exits. It consists of a central post supporting as series of steps arranged in the form of a spiral.
- At the end of the steps, a continuous handrail is provided.
- Such as stairs are provided where space available for stairs is very much limited. As per below fig. shows this typical spiral stair. Steel, Cast iron, or R.C.C. is used for building these stairs.
#6. Bifurcated stairs
- Apart from open newel and dog-legged types turns, stairs may turn in various forms.
- They depend upon the available space for stairs. Quarter-turned half turned with few steps in between, and bifurcated stairs are some of such turned stairs. As per below fig. shows a bifurcated stair.
Parts of Staircase, Parts Names & Details
- Starting step or Bullnose
- Banister, Railing or Handrail
- Core rail
- Base Rail or Shoe Rail
- String or Stringer
- A flat surface, especially one in a series, on which to place one’s foot when moving from one level to another. all step is composed of tread and riser.
- Tread is a scrap of the stairway that’s stepped in. It’s the top or flat surface to press beneath the feet.
- It’s trodden on while climbing or descending the staircase.
- It’s constructed to the same thickness as another floor. There’s always one fewer tread than risers at stairs.
- The general horizontal distance of the stairs is going to be the number of threads added together.
- The horizontal projection of a step in a staircase is called tread. It is also known as going
- In residential buildings, the tread length provided is 250 mm while in public buildings maximum length 270 mm to 300 mm.
- The following empirical formula is used to decide rise and tread:
- 2R + T > 550 mm but < 700 to 600 mm
- where R is a rise in mm, and T is tread in mm.
- This riser is the vertical portion between each tread on the stair.
- Not all stairs have risers. The rise-less steps are called the open thread.
- Open riser stairs have grown in popularity Recently years. Closed tread stair has risers included.
- This vertical board forms the face of the step, also forms the space between one step and the next.
- Rise provided could be uniform. It is normally hight 150 mm to 175 mm in residential buildings while it is kept between hight 120 mm to 150 mm in public buildings.
- However, in commercial buildings, more rise is provided from the consideration of the economic floor area.
- Nosing is the flat protruding edge of a stair at which most foot traffic occurs.
- Mostly, it’s the half curved molding fixed into the ends of those threads exposed at a half that covers where the balusters fit into the treads.
- Nosing is the border of the tread projecting beyond the face of the riser and the face of a cut string. This is the place where the thread above a riser overhangs it. Sometimes, the tread may not have a nosing.
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#5. Starting step or Bullnose
- Where stairs are open both sides or on one or, the first step above the lower floor might be wider than the other steps and round.
- The balusters usually form a semicircle around the circumference of the rounded portion, and the handrail has a horizontal spiral known as a”volute” which supports the top of the balusters.
- Aside from the cosmetic appeal, beginning steps allow the balusters to form a wider, more stable base at the end of the handrail.
- Handrails that simply end in a post at the foot of the stairs can be sturdy, in spite of a thick post. A double bullnose may be used when either side of the staircase is open.
#6. Banister, Railing or Handrail
- The angled member for handholding, as distinguished by the vertical balusters that hold this up for stairs which are open on either side; there is often a railing on each side, sometimes only on one side or maybe not at all, on wide staircases, there’s sometimes also one at the middle or more.
- Banister Definition: The term”banister” is sometimes utilized to mean just the handrail, or sometimes the handrail and the balusters, or sometimes just the balusters.
- A volute is a handrail end element for its curtail or bullnose footsteps that curve inward, such as a spiral. It’s said to be left or right-handed, depending on which side of the handrail is as one faces up the stairs.
- The detail is similar to a scroll in the entry of a handrail, sometimes known as a monkey’s tail. Available with an up-ramp, it’s installed in the bottom of this side on a starting step, extending out from this side of the staircase.
- But, it’s the most difficult installation procedure you are able to find in a staircase
- A gooseneck is a vertical handrail that joins a sloped handrail into a higher handrail on the landing or balcony.
- It’s the part of the stair hand railing. Gooseneck= Vertical turn + Up-ramp. Goosenecks come in a variety of sizes and shapes.
- Do not purchase a gooseneck that does not match with your handrail.
#9. Core Rail
- The wood handrails often have a metal core to provide extra stiffness and strength, especially when the rail must curve against the grain of their wood.
- As per archaic term for the metal, the core is”core rail.“
- Wall handrails are mounted directly as per the wall with wall brackets.
- In the bottom of the stairs, such railings flare into a flat railing, and this horizontal portion is known as a”starting easing.”
- On top of the stairs, the horizontal portion of the railing is known as an “over easing.”
- The combined framework of handrail and baluster is called as a balustrade.
- The collective name for the parts Spindles, Base rail, Handrail, Newel post.
- A term for the vertical posts that hold up the handrail. Also called guards or spindles.
- Treads require two balusters. The second baluster is nearest to the riser and is taller than the first.
- The extra height of the second baluster is typically at the center between decorative elements on the baluster.
- This way, the bottom decorative components are aligned with the top, and the tread components are aligned using the railing angle.
- Newel Post This is the vertical post placed at the top and bottom ends of flights supporting the handrails.
- The caps into the top of a newel post, particularly at the end of the balustrade
#14. Base Rail or Shoe Rail
- For systems in which the baluster doesn’t start at the treads, they go to a base rail. This allows for identical balusters, avoiding this second baluster problem.
- It is a straight step having a parallel width of the tread.
- This is a platform provided between two flights.
- This is the width of the tread between two successive risers. In other words, it is the horizontal distance between the faces of two consecutive risers.
- They are tapering steps used for changing the direction of a stair.
#19. String or Stringer
- This is a sloping member which supports the steps in a stair.