civil engineering thumb rule

Thumb Rules For Civil Engineers

Thumb Rules For Civil Engineers is essential for any civil engineer, Site engineer or civil supervisor. They play a crucial role while taking quick decisions on site. Thumb rules help you in finding out the solution using a simple mathematical formula and make smart decisions whenever needed. But, while using these thumb rules, you must remember that the thumb rule never gives the exact or accurate results, you just have used them for approximate results.

There are numbers of thumb Rules For Civil Engineers which we used in construction work. So, following are some most frequently used Thumb rules on Construction site.

The Thumb rule method is an approximate & comparing method. In thumb rules and the units are not the same when we compare to get the results. So, ignore units while performing thumb rule.

Thumb rule for estimating the Concrete Volume with respect to the area:

The volume of concrete required = 0.038 m3/square feet area

Example:-If Plan Area = 40 x 20 = 800 Sq. m.

So, for the plan area of 800 Sq. m. area the total volume of concrete required

= 800 x 0.038m3 = 30.4m3

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.

you can also use BN Datta recommendations for the more accurate result:

The following recommendations Thumb Rules For Civil Engineersare given in B N Datta for the Steel quantity used in different members of the building

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

Example:

How to calculate the steel quantity of slab having the Length, width, and depth of the slab is 5m x 4m x 0.15m

Step 1: Calculate the Volume of Concrete

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

= 3m3

Step 2: Calculate the steel quantity using formula

As per the guidelines are given in B N Dutta reference book the steel quantity of slab is 1% of the total volume of concrete utilized.

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 = 3 x 7850 x 0.01 = 235Kgs

For accurate estimation, you can refer to Bar Bending Schedule

Thumb Rules For Civil Engineers 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 have 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 gams of Nails used in shuttering of 1m2 area.

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

Thumb rule for Shuttering oil estimation :

Shuttering oil is apply on 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.

Building Estimation videos

Thumb rule used for Cement, Sand, Coarse Aggregate Quantity in Different grades of Concrete :

Note: 1 bag of cement = 50Kgs

Thumb rule for Cement required in Brickwork, Cement Masonry & Plastering work in construction:

Thumb Rules For Civil Engineers for Brickwork:

Brickwork for 1m3 Cement Qty in m3 Cement Qty in Bags
230 mm Brickwork
0.876m3 25.4 Bags
115 mm Brickwork 0.218m3 6.32 Bags

Thumb Rules For Civil Engineers for Cement Masonry Quantity:

Cement Masonry Type & MixCement Qty in BagsCement Qty in Kgs
200mm in Cement Masonry work
of ratio 1:6
0.124Bags/m2
6.2Kgs/m2
150mm in Cement Masonry work
of ratio 1:6
0.093Bags/m2
4.65Kgs/m2
200mm in Cement Masonry work
of ratio 1:4
0.206Bags/m2
10.3Kgs/m2
150mm in Cement Masonry work
of ratio 1:4
0.144Bags/m2
7.2Kgs/m2
100mm in Cement Masonry work
of ratio 1:4
0.103Bags/m2
5.15Kgs/m2

Thumb Rules Plastering Quantity :

Type of Plastering Cement Qty in Bags Cement Qty in Kgs
Rough Plastering
0.09 Bags/m24. 5Kgs/m2
Internal Wall Plastering
0.09 Bags/m24.5 Kgs/m2
Duct Plastering
0.09 Bags/m24.5 Kgs/m2
External Wall plastering
0.175 Bags/m28.75 Kgs/m2
Stucco Plastering
0.175 Bags/m28.75 Kgs/m2
Lathen Plastering
0.55 Bags/m227.5 Kgs/m2

Watch Practical Calculation YouTube Video

13 comments

  1. The volume of concrete required = 0.038 m3/square feet area

    Example:-

    If Plan Area = 40 x 20 = 800 Sq. Ft.

    So, for the plan area of 800 Sq. Ft. area the total volume of concrete required

    = 800 x 0.038m3 = 30.4m3o

    Sir, plan area square feet Mai hai aur concrete density cubic meter Mai ? It is right sir?

  2. Sir.
    I like your video and i learned a lot i am doing my architecture Technology Bsc at DMU Leicester university.
    Sir whatever knowledge i got from you is really valuable please send me very new videos and PDF .

    Thanks
    A lot for teaching

  3. In have 2plots. 23*29. Second 25*36. TOTAL LENGTH 48. IF I TAKE SQURE 48*29. PLS HELP ME FOR G+ 2 PLAN . GROUND.FLOOR FOR OWNER 1 AND 2 FLOOR FOR RENTAL

  4. I leaning for more Impermation at this web site. All comments is very correct and easy to leaning the method.

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