How to Estimate Concrete Volume for Staircase??

Estimating concrete volume for staircase is a little bit tidy as it is inclined and has geometrical shapes. But we can do that easily using some formulas.

Let’s first know deeply about a staircase.

Staircase and Its Parts

A staircase is an essential part of a building which is provided to make a path between two floors.

A staircase has mainly two parts – Step and Landing.

Step: A step is normally a triangular shaped part of a staircase which sits on an inclined slab (Waist slab). A step also has two parts – Riser and Tread.

Riser: Riser is the vertical portion of steps. Normally, the height of a riser is 6 inches.

Tread: It is the horizontal part of a step. The width of a tread is normally kept 10 inches.

Landing: It is a horizontal slab which is provided in between the flights of a staircase. It is mainly provided for changing moving direction of a stair. It also gives users comport to climb.

Flight: A staircase normally has two flights. One is below the landing and another is above the landing.

The flight below the landing is called first flight and the flight above the landing is called 2nd flight.

This is somehow an anatomy of a staircase.

To estimate concrete volume for a staircase, you need to calculate all these parts of a staircase.

Let’s see how we can do that.

How to Estimate Concrete Volume for a Staircase?

Estimating concrete volume for a staircase, you need to calculate the concrete volume for,

• Steps and waist slab of 1st flight

• Steps and waist slab of 2nd flight, and

• Landing.

See the image below. In the image, we have a plan of a staircase.

Now Let’s calculate the concrete volume for the staircase.

Concrete volume for 1st flight of the staircase

From the above two images –

Riser = 6 inches

Tread = 10 inches

Length of a step = 4 feet

Number of steps = 9

Thickness of waist slab = 6”

Concrete volume for the waist slab

To know the concrete volume for the waist slab, we need to calculate the inclined length of the waist slab.

Inclined length of waist slab isn’t normally shown in the drawing. But we can calculate that from the architectural plan.

let’s calculate.

Horizontal length of a waist slab is,

=number of steps x tread

= 9 x 10”

= 7′-6”.

The height of the landing top from floor is,

= number of riser x height of riser

= 10 x 6″ [number of riser = number of steps = 1]

= 5 feet.

So the inclined length of the waist slab is,

=√{(horizontal length)2 + (Height)2}

= (7’-6”)2 + (5’)2

= 9’ (round up)

So, the concrete volume for the waist slab is,

= inclined length of waist slab x width of waist slab (width of a step) x thickness of waist slab

= 9’ x 4’ x 6”

= 18 cubic feet

Concrete volume for steps

As steps are triangular shape so the volume of a step is,

= ½ x tread x riser x length of step

= ½ x 10” x 6” x 4

= 0.84 cubic feet

As we have 9 numbers of steps in a flight, so the concrete volume for the steps of first flight is,

= 9 x 0.84

= 7.56 cubic feet

So the total concrete volume for the 1st flight of the staircase is,

= Waist slab concrete + steps concrete

= 18 + 7.56

= 25.56 cubic feet

Concrete volume for 2nd flight of the staircase

As the 1st flight and 2nd flight are same in our example drawing (above image) so the concrete volume will be same. That is,

= 25.56 cubic feet

Now, we need to calculate the concrete volume for landing.

Concrete volume for the stair landing

From our example drawing,

Length of landing = 8’-6”

Width of landing = 4’-6”

Thickness of landing = 6”

So, the concrete volume for the landing is,

= 8’-6” x 4’-6” x 6”

= 19.12 cubic feet

So, total concrete volume for the staircase is,

= 1st flight concrete + 2nd flight concrete + landing concrete

= 25.56 + 25.56 + 19.12

= 70.24 cubic feet

Estimating concrete volume for a staircase isn’t so difficult. We just need to apply some geometric formula.

Nowadays, getting concrete volume for any shape of a structure is just a matter of few clicks in AutoCAD.

But, in a construction project, we don’t always have access to computers. So, often we need to do it manually.