Thumb Rules In Building Construction For Civil Engineers | Important Point Of Civil Engineering | Construction Thumb rules

Thumb rules are used for quick decision making and are approximate estimates. Thumb rule can never be perfect or accurate.

Site engineer and supervisor are greatly benefited by thumb rules to arrive at quick decision.

Every civil engineer or site supervisor shall have basic knowledge about certain civil engineering basics. The below-mentioned are must-have knowledge about civil engineering and practical knowledge. We will cover in-depth knowledge about civil engineering field and practice.

This post will contain civil engineering tips and tricks That will be of immense importance to civil engineers.

We have shared an extensive list of thumb rules used in construction for various activities. If you get to benefit from it then please share.

Building construction thumb rule
Thumb rules in building construction

Thumb Rules In Building Construction Cost

Thumb rule for construction cost estimates can speed up the rough estimation process. Based on thumb rules in civil engineering, one can have approximate cost and material and labour requirement as well.

Basic thumb rule for Building material requirements and building work per unit area is given below:

Sr. No.Material/ WorkThumb Rule
1.Cement0.5 Bags/sqft
2.Steel3 to 5 Kg/sqft
3.RMC0.05 m3/sqft
4.Blockwork12.5 no./m2
5.Structural Civil Work₹ 751.25/sqft
6.Finishing Works₹ 470/sqft
7.Electrical Cost₹ 133/sqft
8.Plumbing Cost₹ 126/sqft
9.Fire Fighting Cost₹ 40/sqft
10.External Development Cost₹ 94.5/sqft

Thumb rule for construction cost of building material percentage wise

Chart by Visualizer
DescriptionThumb rule (% of Total Cost)
Cement16.4%
Sand12.3%
Aggregate7.4%
Steel24.6%
Painting material4.1%
Tiles8%
Bricks4.4%
Window3%
Doors3.4%
Plumbing5.5%
Electrical6.8%
Sanitary4.1%

Thumb rules for construction cost

The average cost of Construction based on the quality of construction is shown below.

Sr. No.Construction based on QualityThumb Rule
1.Basic Quality Construction1100 Rs./Sqft
2.Medium Quality Construction1400 Rs./Sqft
3.High Quality Construction1800 Rs./Sqft

Thumb rule for average cost of construction for 1000 sqft house.

Sr. No.Description of WorkAverage Cost for 1000 sqft home
1.Cost of ArchitectRs. 15,000 Onwards
2.Brick wall without RCCRs. 800 per sqft
3.Brick wall With RCCRs. 900 per sqft
4.Civil WorkRs. 1500 per sqft
5.Electric and PlumbingRs. 2500 per sqft
6.Raw Material CostRs. 7 Lakh Onwards

Thumb rule for building cost based on whole project cost in terms of percentage.

Sr. No.WorkCost
1.Excavation and Filling Earthwork0.5%
2.Foundation5%
3.Damp Proof Course1%
4.Brickwork34%
5.Roofing20%
6.Flooring6%
7.Doors and window16%
8.Plastering10%
9.White Washing2%
10.Miscellaneous5.5%

Cost of building general thumb rules

Sr. No.WorkThumb Rule
Cost of Material and Labour
1.Material Cost70% of Building Cost
2.Labour Cost30% of Building Cost
Direct and Overhead Cost
1.Direct Cost85% building cost
2.Overhead expense15% of Building Cost
Foundation and Superstructure
1.Cost of Foundation15% of Building Cost
2.Cost of Superstructure85% of Building Cost
Electrical and Sanitary Work
1.Plumbing and sanitation cost8% of Building Cost
2.Cost of Electrical Work8% of Building Cost

Thumb Rule For Slab

  • The minimum thickness of slab is 125mm.
  • The minimum diameter of bars used in slab is 8mm.
  • Fe 500 Steel should be used in the slab.
  • Clear cover of 15mm to 20mm should be provided in slab.
  • Maximum diameter of bars used in slab is 1/8th times of slab thickness.
  • Steel required in slab is 1% of the total volume of concrete.
  • M15 Grade of concrete or above it should be used in slab.
  • Spacing between reinforcement in slab should not be less than 150mm c/c.

Thumb Rule For Beam

  • Steel required in beam is 2% of total volume of concrete.
  • Minimum clear cover of 40mm shall be provided in beams.
  • M20 grade of concrete should be used in beam construction.
  • Minimum 4 bars shall be provided in beams. 2 bars of 12mm at top and 2 bars of 10mm at bottom.
  • M15 Grade of concrete or above it should be used in slab.
  • Spacing between reinforcement in slab should not be less then 150mm c/c.

Recommended for You:

  1. Standard Size of column in building
  2. Concrete and Cement Complete Information | Thumb Rules For Cement and Concrete Work
  3. Standard Height of Plumbing Fixtures – Detailed Information
  4. Standard Room Sizes and Room Area – Detailed Information
  5. Steel Price Per Kg Today in India 2022

Thumb Rule For Column

  • Steel required in Column is 2.5% of total volume of concrete.
  • Minimum steel requirement in column = 0.8% of gross area of concrete
    Maximum steel requirement in column = 6% of the gross area of concrete
  • Spacing between Longitudinal reinforcement should not be more than 300mm.
  • Minimum clear cover in column is 40mm. 25mm clear cover is provided if column is less than 200mm.
  • Minimum dia of 12mm bars 4 numbers should be used in column.
  • The maximum diameter of reinforcing bars in column should be not more than 50mm.
  • Overlapping distance in longitudinal bars should not be less than 24 times the smallest bar dia.
  • Maximum spacing of stirrups is 16D or B or 300mm whichever is less.
  • Minimum size of column should not less then 9″ X 9″.
  • For G+1 Structure 9″ X 12″ (225mm X 300mm) Column should be used.
  • Maximum space between two column of size 9″ X 9″ should not be more than 4 meter.
  • M20 Grade of concrete should be used in concreting column.
  • Fe 500 Steel is also recommended for column reinforcement.
  • Column should be equally spaced in a grid so as to efficiently transfer the load.

Thumb Rule for Foundation

  • Steel required in footing is 0.8% of total volume of concrete
  • The clear cover of main reinforcement in footing is 50mm.
  • A minimum 10mm bar shall be used for foundation footing.
  • M20 grade of concrete or above should be used for foundation.
  • Length, width and depth of foundation should not be less than 1 meter.
  • Footing thickness should not be less then 40 cm.
  • Pile foundation should be used if soil bearing capacity is less than 24 kN/m3.

Thumb Rule For Labour Productivity

Manpower productivity estimates are useful for calculating number of labour or man required to perform a task.

Labour output per day in construction activity can help to estimate the number of labour required to perform a particular work or task.

Manpower productivity estimates are shown below:

Sr. No.ActivityManpowerOutput (8Hrs)
1.BrickworkMason – 1
Male Mazdoor – 0.75
Female Mazdoor – 0.5
45 cuft
2.Wall PlasteringMason – 1
Male Mazdoor – 1
Female Mazdoor – 0.5
120 sqft
3.Ceiling PlasteringMason – 1
Male Mazdoor – 0.75
Female Mazdoor – 0.5
90 sqft
4.Shuttering WorkCarpenter – 2.25
Foremen – 0.2
Helper – 2.25
11 m2
5.Steel WorkBar Bender – 1
Helper – 1
150 kg
6.Tiling WorkTile Mason – 1
Helper – 1
10 m2
7.Block WorkMason – 2
Male Mazdoor – 1.75
Female Mazdoor – 1.75
2 m3
8.Earth WorkMale Coolie – 5
Female Coolie – 4
1000 cuft
9.Painting WorkPainter Skilled – 1600 sqft
10.CarpenterCarpenter skilled – 1
Helper – 1
4 m2
11.Steel BindingFitter – 1
Helper – 1
250 Kg
Thumb rule for manpower calculation

From the above standard labour productivity in construction, we can calculate labour requirement and estimation.

Suppose for shuttering work, we need to know shuttering carpenter productivity per day. From the above thumb rule of labor,

For doing 11 m2 of work, Shuttering carpenter productivity per day is,

  • Carpenter – 2.25
  • Foremen – 0.2
  • Helper – 2.25

Thumb Rule For Reinforcement

Calculation of steel is important as it is one of the costliest building material.

  • Lapping is not allowed for the bars more then 36mm dia.
  • Longitudinal reinforcement in structural members shall not be less then 0.8% and not more the 6% gross cross-sectional area.
  • Atleast 4 bars should be used in square column and 6 bars in circular column section.

Important thumb rule for calculating steel based on building type and for structural members like slab, beam, column and footing is very useful.

Thumb rule for steel in building construction is shown below:

Sr. No.Type of BuildingThumb rule for Steel (Kg/Sqft)
1.Residential Building4.5 – 4.75
2.Commercial Building5 – 5.5
3.Heavy Structure or Tall Mass projects6 – 8
Steel Requirement

The above thumb rule for steel in RCC estimation is not so accurate. For more approximate quantity of steel requirement refer B N Datta as shown below. Steel percentage in concrete as per IS code for different members is shown below:

Sr. No.Member of BuildingPercentage of Steel
1.Slab1% of Total Volume of Concrete
2.Beam2% of Total Volume of Concrete
3.Column2.5% of Total Volume of Concrete
4.Footing0.8% of Total Volume of Concrete
Steel Requirement thumb rule

Example for steel requirement

Calculate steel requirement of slab of dimension 3m X 5m X 0.15m

Total volume of concrete = 3 x 5 x 0.15 = 2.25 m3

Steel required = 2.25 X 1% …(1% taken from table for slab)

=0.0225 m3

For weight of steel multiply by density of steel that is 7850kg/m3. As 1 cubic meter of steel weight 7850 Kg.

Weight of steel required = 0.0225 X 7850 = 176.625 Kg

The weight of steel calculated from the above method is approximate, for accurate quantity use bar bending schedule.

Weight of Steel Bars Per meter length

For calculating weight of steel or reinforcement per unit length following thumbrules can be used.

Weight of steel = D2/162

For length L, Weight of r/f = (D2/162) X L

Weight of steel bars per unit length for different diameter of bars are shown below:

Sr. No.Diameter of BarsWeight of steel bar per meter
1.6mm bar0.222 kg
2.8mm bar0.395 kg
3.10mm bar0.616 kg
4.12mm bar0.888 kg
5.16mm bar1.578 kg
6.20mm bar2.466 kg
7.25mm bar3.853 kg
8.32mm bar6.313 kg
9.40mm bar9.865 kg
Thumb rules for weight of steel bars

Thumb rule for steel quantity is shown below:

  • Thumb rule for steel in kg/m3 for 6mm dia bar is 0.222 Kg.

Thumb Rule For Concrete

Concrete volume can be easily calculated if you know the plan area.

Thumb rule for calculating concrete volume = 0.038 m3 per square foot of plan area.

Thus if floor plan of a house is 30 X 20,

then total plan area= 600 sqft

volume of concrete = 600 X 0.038 m3 = 22.8 m3

Thus total volume of concrete to build 600 sqft house is 22.8 m3.

Concreting work can be done easily at site if proportion of cement, sand and aggregate are known. Based on the mix design of concrete, ratio of cement, sand and aggregate changes, which can be seen in the table given below.

Sr. No.Concrete MixRatioCement Qty (Bags)Coarse Aggregate (m3)Fine Aggregate (m3)
1.M51:5:102.820.980.49
2.M7.51:4:83.480.970.48
3.M101:3:64.500.900.45
4.M151:2:46.600.880.44
5.M201:1.5:38.400.840.42
6.M251:1:211.090.770.39

Thumb Rule For Concrete Mix Design

  • In 1 cu.mt of freshly mixed concrete, if 4 liter of water is added then,
  1. Slump value will increased by 25mm
  2. Compressive strength of concrete will decrease by 1.5 N/mm2 to 2 N/mm2
  3. Shrinkage potential will be increased by 10%
  4. 25% of cement bag will be wasted
  • If temperature of freshly mixed concrete is increased by 1% then,
  1. Slump will be equal to addition of 4 liter of water
  2. Air content will be decreased by 1%
  3. Compressive strength of concrete will decrease by 1 N/mm2 to 1.5 N/mm2
  • If air content of freshly mixed concrete is,
  1. Increased by 1%, then compressive strength will be decreased by 5%
  2. Decreased by 1%, then yield of concrete will be decreased by 0.03 m3 per 1 m3.
  3. Decreased by 1%, then slump of concrete will be decreased by 12.5mm.
  4. Decreased by 1%, then durability of concrete will be decreased by 10%.

Thumb Rule for Concrete Work

  1. Volume of concrete required is 0.038 m3/sqft area.
  2. Standard weight of 1 bag of cement is 50 kg.
  3. 1 bag of cement is equal to 1.25 cuft or 0.0347 m3.
  4. In high rise building 0.5 bags of cement is required per square feet of area.
  5. Density of cement is 1440 kg/m3.
  6. Specific gravity of cement is 3.15
  7. Average cost of concrete is 50 to 80$ per cubic meter.
  8. Initial setting time of cement is 30 minutes and final setting time of cement is 10 hrs.

Thumb Rule for Shuttering Work

Shuttering is required for pouring concrete so that it take appropriate shape. Shuttering is important part of building construction.

Cost of shuttering is almost 15% to 18% of the total cost of building. Thus if shuttering quantity is not taken appropriately then it can lead to drain of money.

Thumb rule for shuttering is shown below

  1. Shuttering is 6 time the concrete quantity or,
  2. Shuttering is 2.4 times the plinth area

If we need to concrete 5 cubic meter then the shuttering required can be found with thumb rule by multiplying concrete quantity by 6.

Shuttering area = 5 X 6 = 30 m2

Shuttering Members

Different shuttering members are Ply, Battens, Nails.

Shuttering Ply

Shuttering Ply dimension are 2.44 m X 1.22 m X 0.012 m

Number of shuttering ply sheets needed for shuttering = 0.22 X Shuttering Area

Let’s assume we need to concrete 100m area. Then Shuttering needed for concreting is 0.22 time 100.

Ply required for shuttering = 0.22 X 100 = 22 numbers

Battens For Shuttering

General dimension of battens are 75mm X 40mm

Thumb rule for Batten Quantity = 19.82 X Number of Ply

For 22 number of ply, the quantity of battens is = 19.82 X 22 = 436 Battens

Nails and Binding Wire

  • Thumb rule for nails required in shuttering is 75 grams per 1 m2 of shuttering.
  • Thumb rule for binding wire is 75 grams per 1 m2 of shuttering area.

Shuttering Oil

Oil is applied on shuttering surface for easy removal of shuttering. Quantity of oil needed for shuttering is

  • 0.065 times total shuttering area
  • For 15 m2 of shuttering, 1 liter of oil is needed

For 100m2 of shuttering oil needed for shuttering = 0.065 X 100 = 6.5 liter

Sr. No.MemberThumb Rule
1.Shuttering Area6 times the concrete area
or
2.4 times the plinth area
2.Shuttering Ply0.22 times Shuttering Area
3.Battens19.82 times Shuttering Ply
4.Nails 75 grams per 1 m2 of shuttering area
5.Binding Wire 75 grams per 1 m2 of shuttering area
6.Shuttering Oil0.065 times total shuttering area
or
For 15 m2 of shuttering, 1 liter of oil is needed

Thumb rule for removing Shuttering

Shuttering should be remoced only after the member has attained suitable strength. Below table mentions detail about removal of shuttering duration.

Sr. No.Member of StructureDays
1.Sides of foundation, column, beams and walls2 days
2.Sides of span larger then 4.5 meter14 days
3.Sides of span shorter then 4.5 meter7 days
4.Sides of beams and arches upto 6 meter span14 days
5.Sides of beams and arches from 6 m to 9 m span21 days
6.Sides of beams and arches above 9 meter span28 days

Thumb Rule For Brickwork

Number of Bricks required in 1 cubic meter = 500 number

Suppose for 20m3 of brickwork is needed to be done

Then the quantity of brickwork required for 20m3 of brickwork = 20 X 500 = 10000 bricks.

Thus 10000 number of bricks is required for brickwork of 20m3.

Quantity of cement required in 1 m3 of brickwork for different size of brickwork varies. Below is a thumbrule for brickwork cement required.

Sr. No.Brickwork sizeCement required (m3)Cement Quantity (Bags)
1.230mm Brickwork0.876 m325.4
2.115 mm Brickwork0.218 m36.32
Thumb rule for brickwork.

Thumb Rule for Brickwork for different mix ratio thickness of brickwork along with cement sand required are given below.

Sr. No.BrickworkMix RatioMortar Thick (mm)Cement Qty (Bags/m3)Sand (m3)
1.100 mm thick1:4100.150.035
2.200 mm thick1:6101.40.30
3.200 mm thick1:5101.70.25
4.200 Blockwork1:5100.150.02

Thumb rules of bricks

  • Standard size of bricks is 19cm X 9cm X 4cm.
  • Weight of first-class clay bricks should be 3.85 kg.
  • Crushing strength of bricks is 10.5 MN/m2.
  • Water absorption in bricks is 12% to 15%.
  • Compressive strength of bricks is 36 KN/cm2.
  • Number of bricks in 1m3 of brick masonry is 550 bricks.

Thumb Rule For Plastering

Based on experience and practice following thumb rule for plastering is used in construction and building work.

Cement required changes according to type of plastering. Cement required for internal plastering is comparatively lower then cement required for external plastering.

Below is a table containing cement requirement for different type of plastering work.

Sr. No.Plastering TypeCement Qty (Bags/m2)Cement Qty (Kg/m2)
1.Internal Plastering0.094.5
2.External Plastering0.1758.75
3.Rough Plastering0.094.5
4.Duct Plastering0.094.5
5.Lathen Plastering0.5527.5
6.Stucco Plastering0.1758.75
Thumb rule for cement required in plastering

Cement sand requirement for wall and ceiling plastering are shown below:

Sr. No.Plastering TypeRatioPlaster Thickness (mm)Cement (Bags/m2)Sand (m3/m2)
1.Internal wall Plaster1:3150.160.017
2.External Wall Plaster1:4200.170.024
3.Ceiling Plaster1:2120.170.012
4.Rough Plaster1:5160.110.020

Thumb Rule For Cement Masonry Work

Cement requirement in masonry work varies according to cement masonry type and mix. Quantity of cement required for different cement masonary work and mix is shown below.

Sr. No.Masonry Type and MixCement Qty (Bags/m2)Cement Qty (Kg/m2)
1.200mm Masonry Work (1:6)0.1246.20
2.150mm Masonry Work (1:6)0.0934.65
3.200mm Masonry Work (1:4)0.20610.30
4.150mm Masonry Work (1:4)0.1447.20
5.100mm Masonry Work (1:4)0.1035.15
Thumb rule for cement masonry work

Thumb Rule for Flooring

Quantity of cement required for laying of flooring can be calculated based on the thumb rule given below.

Sr. No.Type of FlooringThumb Rule for cement
1.Marble Flooring0.3 Bags/m2
2.Marble Skirting0.025 Bags/m
3.Marble Glading0.27 Bags/m2
4.Terrace Flooring0.3 Bags/m2
5.Granolithic Flooring0.25 Bags/m2
6.Mangalore Tile0.35 Bags/m2
7.Ceramic Flooring0.3 Bags/m2
8.Vitrified Tile Flooring0.28 Bags/m2
9.Vitrified and ceramic tile dado0.25 Bags/m2
10.Anti skid Flooring0.28 Bags/m2
Thumb rule for flooring work

Thumb Rule for Water Proofing

Sr. No.Water Proofing workThumb rule
1.Water proofing for sunk slab0.25 Bags/m2
2.Water proofing for walls0.25 Bags/m2
3.Water proofing for toilets0.63 Bags/m2

Thumb Rule for Cement

Bulk Density of Cement

Density of cement according to type are shown below:

Sr. No.Cement TypesDensity (kg/m3)Density (KN/m3)
1.Lime mortar1600-184016-18
2.Ordinary Cement144014.4
3.Plain Cement Concrete240024
4.Pitch101010.1
5.RCC250025
Bulk density of cement

Below is a list of cement types and initial and final setting time of respective cement.

Sr. No.Type of CementInitial Setting TimeFinal Setting Time
1.Ordinary Portland Cement (33 Grade)30 minute600 minute
2.Ordinary Portland Cement (43 Grade)30 minute600 minute
3.Ordinary Portland Cement (53 Grade)30 minute600 minute
4.Sulphate Resistant Cement30 minute600 minute
5.Portland Pozzolona Cement30 minute600 minute
6.Rapid Hardening Cement30 minute600 minute
7.Slag Cement30 minute600 minute
8.High Alumina Cement30 minute600 minute
9.Super Sulphated Cement30 minute600 minute
10.Low Heat Cement60 minute600 minute
11.Masonry Cement90 minute600 minute
12.IRS T-4060 minute600 minute
Initial Setting Time and Final Setting Time of Cement

Thumb rule for Achieving Economy

In order to save money in building construction, one has to follow certain guidelines and thumb rule. Following these thumb rules for building construction will result in saving money and economic building.

  1. Use formwork as many time as possible to achieve economy.
  2. Minimum floor to floor height will result in saving of money.
  3. Column layout should be placed in a uniform grid.
  4. Standard column size should be used.
  5. Same depth of beam should be used, if possible.
  6. Local available material should be used to minimise cost.
  7. High strength concrete should be used.
  8. To remove formwork earlier high early strength concrete should be used.
  9. To minimise honey combing and air pockets in concrete self consolidating concrete should be used.
  10. Avoid congestion of steel especially at beam column joints.
  11. Use large size bars in column and smaller size bars in slab.

Frequently Asked Questions

Some of the most frequently asked question in civil engineering are shown below.

How many kg of steel is required in 1m3 of concrete

7850 kg of steel is required in 1m3 of concrete

What percentage of steel in slab as per is 456

Minimum percentage of steel in slab is 0.8% and maximum percentage of steel in slab is 4%.

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