# How to estimate material for spherical domes or sloped slab

In this construction video tutorial, learn the detailed process for computing materials toward domes or sloped slab specifically toward half spherical domes and segmental domes. The tutorial will be very useful for quantity surveyors.

The tutorial focuses on the following points :-

1) surface area and volume of solid as well as hollow sphere which will facilitate you to make calculation for domes easily.

2) Cement, Sand, crushed stone, steel and surface paint /plaster/tiles area or any other material which are estimated in form of area toward half spherical dome.

3) Cement, Sand, crushed stone , steel and surface paint /plaster/tiles area or any other material which are estimated in form of area toward segmental spherical dome.

For making estimation of solid sphere, the formula for finding out the sphere volume should be 4pR3/3.

For making estimation of hollow sphere, the formula for finding out the sphere volume should be 4p(R3-r3)/3 and surface area = 4 pR2

Here, in this video, solution is given for a problem where you have to calculate the cement, sand, crushed stone and steel for specified spherical dome.

The ratio of concrete is given as 1:2:4 and steel is 1.5%. Number 4 bar is used. Calculation is also made for external surface paint.

Read Also: How to find out the quantity of concrete in a semi sphere slab

To get more details, watch the following video tutorial.

Video Source: Engineer Boy