Thumb Rules For Civil Engineers In Building Construction

Thumb Rules For Civil Engineers In Building Construction

Thumb Rules For Civil Engineering is essential for any Civil Engineer, Site Engineers, or Civil Supervisor. They play a crucial role while taking quick decisions on site. There is some Civil Engineering Basic Knowledge that every Civil Engineers must know about this Riles.

The Thumb Rule of Civil Engineering or the thumb rule for construction helps you in finding out the solution using a simple mathematical formula & make smart decisions whenever needed.

But while using these thumb rules, u must remember that the thumb rule never gives the exact or accurate results, u just have used them for approximate results

There is a number of Thumb Rule For Civil Engineers that we used in construction work. So the following are some most frequently used Thumb rules on the Construction site.

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

 

1. Thumb Rules for Civil Engineering In Construction

Following are thumb rules in Civil Engineering 

1. Thumb Rule for Concrete Volume

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. the area the total volume of concrete required

= 800 x 0.038m3 = 30.4m3

Learn More 

What Is Difference Between Pre-tension And Post-tension

2. Thumb Rule for Steel Quantity for Slab, Beams, Footings & Columns

Following are some Important thumb rules for Steel Calculation for Slab, Beam, Column, and Footings.

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 Data Recommendations for the more accurate result,

The following recommendations Thumb Rules For Civil Engineering are given in B N Data for the Steel quantity used in different members of the building.

 

3. Percentage of Steel in Structural Members

Following are thumb rules for reinforcement in concrete members,

1) Slab – 1% of the total volume of concrete (Slab steel calculation thumb rule)
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

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2. How To Estimate Per Meter Weight Of Reinforcing Steel Bar

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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 the BN 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

4. Thumb Rules For Shuttering Work

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

For example, the concrete quantity is 0.5m³, then

Area of Shuttering is 0.5 x 6 = 3m²

Components of Shuttering

Shuttering Ply Quantity estimation

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

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

 

5. 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 grams of Nails were 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.

6. Thumb Rule for Cement, Sand, Coarse Aggregate Quantity Calculations

Note: 1 bag of cement = 50Kgs

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

Learn More

1. How To Calculate The Cutting Length Of Stirrups In Beam And Column

2. How to Calculate Staircase Concrete & Bar Bending Schedule And Staircase Reinforcement Details

3. Cutting length Determination Of a Spiral Or Helix Bar

4. What is crank Length of reinforcement

5. How do you take off a Staircase

7. Thumb Rules For Civil Engineers for Brickwork

following are Thumb Rules for civil engineering for brickwork and cement quantity calculations.

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

 

8. Thumb Rules For Cement Masonry Quantity

Cement Masonry Type & Mix	Cement Qty in Bags	Cement 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

 

8. Thumb Rules Plastering Quantity

 

Type of Plastering	Cement Qty in Bags	Cement Qty in Kgs
Rough Plastering	0.09 Bags/m2	4. 5Kgs/m2
Internal Wall Plastering	0.09 Bags/m2	4.5 Kgs/m2
Duct Plastering	0.09 Bags/m2	4.5 Kgs/m2
External Wall plastering	0.175 Bags/m2	8.75 Kgs/m2
Stucco Plastering	0.175 Bags/m2	8.75 Kgs/m2
Lathen Plastering	0.55 Bags/m2	27.5 Kgs/m2