Thumb rule for site Engineers

1. Thumb rule for Steel quantity required for Slab, Beams, Footings & Columns:

Steel required in residential buildings = 4.5 Kgs – 4.75 Kgs / Sq. Ft.

Steel required For Commercial buildings = 5.0 Kgs-5.50 Kgs/Sq. Ft.

2. Percentage of Steel in Structural Members:

1) Slab – 1% of the total volume of concrete
2) Beam – 2% of the total volume of concrete
3) Column – 2.5% of total volume of concrete
4) Footings – 0.8% of the total volume of concrete

Process of Hiring Architects for construction ?

Example:

How to calculate the steel quantity of slab having the Length, width, and depth of the slab is 9 m x 4 m x 0.125 m

Calculate the Volume of Concrete

The Total Volume of Concrete for given Slab = 5 x 4 x 0.15

= 4.5 m3

Calculate the steel quantity using formula

Thumb rule to estimate Steel quantity of above slab

= Volume of Concrete x Density of Steel x % of Steel of Member

Steel weight required for above slab = 4.5 x 7850 x 0.01 = 353.25 Kg

Thumb Rules to estimate the Shuttering area:

Shuttering costs is taken as 15-18% of the total construction of the building. Shuttering work is done to bring the concrete in Shape. Thumb rule to estimate the shuttering required is 6 times the quantity of concrete or 2.4 times of Plinth area.

For example, the concrete quantity is 0.5m3, then

Area of Shuttering is 0.5 x 6 = 3m2

Components of Shuttering:-

The Shuttering plate Ply, Battens, Nails are components of Shuttering.

Shuttering Ply Quantity estimation:

Suppose, The shuttering Ply has a length, width & depth of 2.44 x 1.22 x 0.012

The No. of Shuttering Ply sheets = 0.22 times of Shuttering

Suppose, the shuttering area = 3m

Then Ply required for shuttering = 0.22 x 3 = 0.66m2

Battens Quantity Calculation:

Shuttering batten usually has a length & width of 75mm x 40mm.

Batten Quantity = 19.82 x No. of Ply Sheets

If work requires 25 Ply sheets, the total quantity of Battens are 19.82 x 25 = 495 Battens

Nails & Binding Wire Quantity in Shuttering:

Approximately, 75 gms of Nails used in the shuttering of the 1m2 area.

75gms of Binding wire is used for every 1m2 of Shuttering.

Thumb rule for Shuttering oil estimation :

Shuttering oil is applied on the shuttering plate surface used to de-frame or de-assemble from the concrete easily.

Total required Shuttering oil  = 0.065 x Total Area of Shuttering

(or)

For every 15m2 of shuttering 1 liter of shuttering oil is consumed.

Example :

If, total area of shuttering is 15 m2, then Shuttering oil Consumption = 0.065 x 15 = 0.975.