Thumb rules for designing a Column layout | Civil Engineering



Guidelines to be followed for making a column layout

In this article, we will go through the essential thumb rules to be followed for giving a column layout. Of-course columns have to be designed in accordance to the total forces acting on the structure, but apart from that, it is essential for every Civil engineer and Architect to remember a few thumb rules so that they are prevented from making mistakes.

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Three thumb rules to be followed are as follows:

  1. Size of the Columns
  2. Distance between Columns
  3. Alignment of columns

Minimum Size of RCC columns

The size of the columns depends on the total load on the columns. There are axial loads and lateral loads. Large beam spans induce bending moment not only in the beams, but also in columns which are pulled by the stresses in the beams. It is important to use advanced structural design software like ETabs or Staad pro. I highly recommend every structural designer learn these software. The thumb rules are for general designing in very small projects.

For this general thumb rule, we will assume a structure of G+1 floors high, using standard 6″ walls.

Minimum size of an RCC column should not be less than 9” x 12” (225mm x 300mm) with 4 bars of 12 MM Fe415 Steel.

These days the minimum I use in my projects is 9″ x 12″ (225 mm x 300mm) with 6 bars of 12 MM Fe500 steel. You can never go wrong with strong columns. I also recommend use of M20 grade concrete for the structure (ratio 1 part Cement : 1.5 parts Sand : 3 parts Aggregate with 0.5 parts water by volume). I recommend use of 8 MM stirrups at a distance of 150 MM center to center throughout the length of column.

This setup of 9″ x 12″ RCC columns is safe for G+1 Floors. There are a lot of other considerations, but this is just a thumb rule.

Span (distance) between two columns

For the above column setup, a span of up to 5 meters is quite safe. One can use beams of size 9″ X 12″ (225 MM x 300MM) with a slab thickness of 5″ (125 MM) cast in M20 concrete for spans up to 5m. There are other considerations like secondary and tertiary spans, point loads and wall loads which have to be considered. It is complicated, but thumb rules can work if the structure is simple. It is always recommended to use structural design software like ETabs or Staad pro for design.

In a beam of up to 5 meters length, secondary spans of up to 4 meters, wall loads of up to 8 kN per running meter, I can use steel as below.

  • Top Steel – 2 bars of 12 MM
  • Crank bars – 2 bars of 12 MM, cranked at an angle of 45Β° at a distance of L/4 at both ends of a simply supported beam
  • Bottom Steel – 3 bars of 12 MM.

This configuration can change depending on a lot of factors.

Alignment of Columns

Placing of columns depend completely on the plan. A planner has a very important job. A grid column placement is always preferred in order to reduce point loads and unnecessary complications while construction. This reduces the cost of construction as well as time required for construction. Beams which have continuity with other simply supported beams have reduced bending moments, and thus require less steel and concrete depth to be safe.

Columns have to be connected with each other for smooth transfer of loads. An experienced planner will keep such things in mind when planning the structure.

In the next article, I will explain these three thumb rules with the help of an example “Column Layout for a Residence“.

Recommended Reading:

Introduction to design of RCC Structures

Building Design Guide which includes design of:

  1. RCC columns
  2. RCC beams
  3. Foundations
  4. Staircase



119 thoughts on “Thumb rules for designing a Column layout | Civil Engineering”

    • There are a lot of books, most of them have the same technical information. My personal favourite was a book by Shah-Kale. Very easy to understand and learn structural design.

      • Sir My plot is 42 feet wide and 100 ft long. Can I construct a 6 floor residential building with 3 columns in width ie 20-21 ft apart using 24β€³Γ—12β€³ columns with 10 rods of 4= 20mm and 6=16mm.
        In length there are 8 columns ie total 8Γ—3=24 columns.
        In length distance between columns – 1st 17ft, 2nd 21ft, 3rd-4th 12ft, 5th-6th-7th 15ft.
        Please reply me with suggestion.

        • Sir, it is impossible to tell from a glance. The only way is to model and analyze the structure in modern structural design software like Staad Pro or ETabs by an experienced professional. That is the only way.

  1. I’m building a 2 storied residential building (800) sq.ft. There are 12 columns. height of each column from base to floor level is 9 ft. I want to make singletie beam of 10×12 at pl level. My engineer suggests me for 2 tie bems, one at 5′ & another at 9′ height. Is it required? pl. mail me

  2. Sorry, if I may sound dumb as I am a new bee.
    What does ‘1 and half storey structure’ mean? A house will be either 1 or 2 storey.

    Also, would it be ok if the column size is 12″x12″ using M15 grade concrete?

    Thanks in advance.

    • Hello Gerard,
      1 and half storey is calculated by adding the length of the plinth beam and the parapet wall. When their lengths are added, they sum up to 5′ which is equivalent to half storey. This is assumed so since they have to be considered in the structural design calculations.
      As far as column size is concerned, the column size for any building is derived from its structural calculations.

      Go through the following article. It will be of help to you.
      Building design Guide | Structural Design

  3. hey.. that was really helpful but can u tell me what should be the size of the columns and c-c distance if we are working on a large area and have to give a barrier free movement like in a hospital?
    also if we plan to give some parts double height.. will that change the dimensions of the column?

  4. Hey,

    tons of useful info on the site. Awesome work. Kudos! Would like to clarify a few things about though – when you say zigzag arrangment of column is wrong what exactly do you mean. i’ve come across projects where there is a basic grid but all the columns may not be alligned to form perfect rectangles. but the beams connecting four columns do form a rectangles. when you say zig zag what exactly do you mean? clarification much appreciated!

    regards,

    Rollson lasrado

  5. sir,i am planned to construct g+1 storey bldg.in my village.foundation depth is 6’on hard strata i.e on hard murum strata.length of house is 50’*10.5′ .pl.advice me about r.c.c. footing, no.of columns placing of columns,reinforced bar details in column, same details about beams and slab

    • Hello Shankpal,

      There is some good news I would like to share with you. Civil projects Online has officially launched its Architectural and Structural Design Services. You can immediately get in touch with them and get the answers to your questions. It is important for you to understand that we cannot generalize the structural design of columns and footings. It needs expertise without which it cannot be constructed safe and sound. We spend lacs of rupees on the construction of our houses because we build them once in our lifetime. Hence, it is important to go the right way and not take chances by deciding the number of columns and footings on our own.
      The entire aim of offering design services at such low costs is so that people belonging to all levels are able to afford it. We want the best for you.

      Take a look and you should definitely get in touch.


      Architectural and Structural Design Services by Civil Projects Online

      Look forward to hearing from you.
      Regards,
      BenzuJK

  6. Hello Sir,

    Thanks for all the posts & your suggestions, it is very helpful for all peoples. Here after reading the post “thumb rules for designing column”, I have some problem. Last year I have constructed my home of G floor & made all column & beam of 9″x9″ with 4 nos. 12mm bars & used M15 concrete. Distance of all column are 12′.

    I want to construct this year one floor more (so G+1), pls suggest whether my home will be at risk or OK to survive. And another thing, Suppose in future I want to construct one more floor, How the same can be achieved???

    ….Ashish Sahu

    • If you do that your house will collapse. Thumb rules are minimum standards and not meant to be used by layman like you. They are to be used under the supervision of a Civil engineer who is an expert in this field. If you need experts working on your project, you should be willing to pay them as well unless you want your house to collapse and your family killed under the debris.

  7. Dear Sir\mam
    I want to know that if we are constructing a 3 storey house than what should be the distance between 2 columns. please tell the minimum distance which can be between the two coloums.

    • There is no minimum or maximum distance. It all depends on the design. You should hire a structural designer. You are building a house for 60 years lifespan. You can get a good structural designer for Rs 7 per square feet builtup area. That is a small investment for complete peace of mind.

  8. I am going to develop parking flplus4 floor building. Plot size is 14m x 5m. Lift is planned. Can u advise no of columns, spacing and re in bar nose and spacing. Advise please.

  9. Hello, i have a question i am building a new floor on my 30 years old G+1 120 yard building. my constructor advising me to repositioning the column above floor he is using term jackling the columns like if its right to left he would reposition it to front to back on previous column.. is it safe and allowed??

  10. Dear Sir,
    we are building a rest house using eco sand bricks and our client need to construct that without concrete column.

    so i need to know if we using 3 nos steel bars which have a 32mm dia as a column in building is okey or not for the load bearing.
    our building has a wood roof

  11. 24’x42′ slab I provide 10 columns size 9″ x18″ ,required three floors ,soil is sand, footing is done 6’x6’x2’6″ sir I want witch size beam required ,steel requirement for beam &slab

  12. Hi, am building a veranda and a beam of 5.2 m is required on 2 round collums each end. Y12 steel will be used for the beam and r 8 stirups at 500mm apart .is it possible?

    • Hi there,
      I would not be able to answer that question as it would me be giving wrong advice. We run a professional civil engineering service where we offer advise (paid). Please email arjaved@gmail.com with you queries and we will take you from there.

  13. If a plot of ground floor is constructed with 6 by 12 pillar. It is provided with 15 pillars. Can I suggest somethings to the client so that he can comfortably construct first and second floors,

    • Hi Ramya,

      There is no thumb rule for minimum or maximum distances. It all depends on the layout of the building and how cleverly an engineer is able to design it to maximise its functionality.

      • I need a column to be designed for a span of 8 Mts and the size of room is 25feet x 68 feet I need the columns only on the sides I don’t need Columns in the center and beam size also .

  14. dear sir.
    my site is 16 feet frontage and 116 feet stretch.i wanna know what will be the column details.if i place 9”x12” with the distance of 10 feet is acceptable or not.

  15. Question 1:>My question is when I use a column size of 10β€³X12β€³ using four 16 mm bars for a G+2 residential house ->What is the distance between the centre of the two columns that should not be exceeded ?
    Questio2:>Also please let me know the maximum distance between the two columns that should not be exceeded when I use 12β€³X18β€³ column sizes with six 16 mm bars for a G+2 residential house.
    Please advise.

    • I wish it was as simple as that Prashant. There is a need for the surveying of the site prior to making calculations for foundations, columns and beams of the building. There is not a set way of doing a column design. I would recommend that you get it designed by a certified Structural Engineer.

  16. Hi
    1) My plot size is 24β€² X 49β€³, and I am planning to construct G+2+Pent House, my engineer planned 11 columns, i.e four C1 (9β€³ X 12β€³), with 16mm 6 bars + 12mm 2bars, four C2 (9β€³ X 12β€³), with 16mm 4 bars + 12mm 2 bars and Three C3 (9β€³ X 9β€³), with 12mm 6 bars. Distance between C1 is 15β€² in all sides, C1 to C2 is 15β€², C2 to C2 is 10β€², Distance between C1 to C3 is 6β€², C2 to C3 is 10β€²

    (This is not distance, column points)
    Columns points fr South West:2β€²(C1),17β€²(C1), 32β€²(C2),43(C2)
    Columns points from South .:2β€²(C1), 17β€² (C1), 32β€²(C2), 43(C2)
    Columns points from East South 2β€² (C3), 32β€²(C3), 43(C3)

    Columns points from West to South East:2’16’ 22β€² (1st Line)
    Columns points from West to East: 2’16’ (2nd Line)
    Columns points from West to East: 2’12’22 (3rd Line)
    Columns points from West to Noth East: 2’12’22 (4th Line)

    My structural engineer is just started his consultancy, I would like reconfirm the strengths. Please help me.

    Please advise

    • The steel is decent but my recommendation would be to increase C1 size to 9” x 18” on ground floor, 9” x 15” on first floor , 9”x12” on second floor and above.
      C2 should be 9”x15” on ground floor, 9”x12” on first floor and above
      C3 should be 9”x12” minimum on all floors.
      Remember to use M20 grade concrete and FE500 steel.

  17. It’s very useful for me…and I also have one doubt …I use 2 nos of 12mm at top and 2 nos of 12 mm at bottom and 2 nos of 10 mm at cent of the beam ….the beam size is 1 feet depth and 9″ breath…the span of beam length is 16′ it will take load or not…

  18. hey… this post is really helpful, thanks. Sir, i need to know what dimension of columns are used in a 15 to 20 storey building and also the span between the two columns.

    • The maximum I have designed is Basement+Ground+10 floors. My largest column was 18″ X 30″, M25 Concrete. The four spans were 18′, 14′, 26′ and 14′.

      Larger structures are a lot more complicated. Newer construction techniques have really helped. I have seen columns of only 9″ thickness, but 12 feet in length in 30+ storey buildings. Mivan formwork technology is being used on a large scale for residential towers. Post-tensioning structures are preferred for commercial and office buildings. Really way above my skill level.

  19. slabs load come on beam than total load come on column ?
    how to do calculation for reinforcemnt
    pls let me know as soon as possible
    thank you

    venka :
    slabs load come on beam than total load come on column ?
    how to do calculation for reinforcemnt
    pls let me know as soon as possible
    thank you

  20. Dear Sir

    How much steel can be saved on moving to High strength steel bars i.e. from Fe 500 to Fe 550?
    Question-1. If we take an example of 20β€³ x 20β€³ column and height – 10′. How to calculate how many TMT bars are required and of what size? Also how to know which concrete grade is required M30 or M40 etc?

    Question-2. If we use Fe 550 from Fe 500, how much percentage saving is there? I mean will there be the reduction in bar size or what? Properties of Fe 550 and Fe 500 below:-

    For Fe 550:- UTS 645 N/mm2, Yield stress 575 N/mm2, %elogation 16%.
    For Fe 500:- UTS 600 N/mm2, Yield stress 525 N/mm2, %elogation 20%.
    Your help is solicited.

    Regards
    Manu

    • Generally, we preselect the grade of concrete and grade of steel to be used based on experience and need. These days, for regular buildings up to 5 floors height, we use M20 concrete and Fe500 Steel. For smaller structures, the client may insist on Fe415 steel. But in my opinion, Fe500 is economical. I have not used Fe550 in my projects, but in my opinion, concrete has a larger effect on the load carrying capacity of a column than steel grade.

      We calculate loads on each individual columns, then calculate the size and steel required. See article — https://www.civilprojectsonline.com/building-construction/calculation-of-loads-for-foundation-design-structural-design/

      In your example of 20″ X 20″ column, the minimum steel according to IS codes, is 0.8% of cross-sectional area, which is 2000 square mm, which comes to around 10 bars of 16 MM, That is the minimum steel for that size of column, cannot go below that.

      Keeping size (20″ X 20″) and steel constant (10 bars of 16 MM), and playing around with concrete grade and steel grade, we can conclude

      If you choose M20 concrete, and Fe500 steel, the load carrying capacity of that column would be 1770 kN.
      If you choose M20 concrete, and Fe415 steel, the load carrying capacity would be 1695 kN.
      If you choose M15 concrete, and Fe415 steel, the load carrying capacity would be 1360 kN.
      If you choose M15 concrete, and Fe500 steel, the load carrying capacity would be 1440 kN.
      If you choose M25 concrete, and Fe415 steel, the load carrying capacity would be 2025 kN.
      If you choose M25 concrete and Fe500 steel, the load carrying capacity would be 2100 kN.

      In the end, a qualified structural designer would be able to give you a good, economical structural design. It is always better to consult a professional for such purposes.

  21. Hi Benzu jk, my house under construction G floor is already completed. it’s a rectangular layout with 3 room having dimension 16*15 feet. since 16 feet is too long as I assume ,and put a support column .the steel bar I used is 4 no.of 16 m and 04 no of 12 mm. size of main column is 12’*12′ and support column is 10’*10′ with 04 no. 12 mm.
    The beam size for G floor was 10′ depth with 6 no of 16 mm with one 12 mm reinforcement on both side of beam.
    but in 1st floor I am making a change , the beam depth is 13′ with 04 no of 16 mm down and 03 no of 16 mm up.
    but my concern is slab size, will be 16*14.5 sq.feet with no beam along the support column.
    SHALL I MAKE SOME CHANGE, GIVE SOME LIGHT AND PLEASE TELL ME POSSIBLE AND SAVE STOREY ,I CAN MAKE.

    • I generally try to maintain beam depth of 12″ excluding slab depth. Also, minimum slab depth standards these days is 5″. I would suggest you approach a local structural designer. it will save you money and give peace of mind.

  22. MY 20 by 45 ft structure have four 9″ by 12″ column and four 9″ by 9″ column having 9″ by 9″ beam and 5″ slab thickness. Column and beam will have 12 mm TMT bars and m20 grade. Building will have G+1 floors only and wall will be of AAC blocks. Total weight of First floor roof and beams is 600 Kn. So please tell me is it a good structure or need improvement.

    • The best option would be to consult a structural designer. In my professional practice, our organization has stopped using 9″ X 9″ columns and beams many years ago. Minimum recommended size should be 9″ X 12″.

  23. I have a technical question, I recently bought a land and started construction in rainy season. When we started digging the land for pillar/footwork, after 4 feet, there was water coming up from few sides of the land, we used dewatering pumps to remove water and laid mat and pillar, even after that the thin water flow from sides didn’t stop, we closed the pillar by spreading soil.

    Could you please tell me will the water beneath the land that was coming during the pillar/footwork construction effects the house.

    Thanks,
    Pavan

  24. Can we design structure for g+2 with entire beam column with m20+ and 8 tmt rebars of multiple sizes 2 –16 mm
    Rest 12mm
    entire structure with rectangular dimension of 24’x48 consisting of 15 columns 3rows of columns but column and slab beam of 6inch x18 inch
    Totaling 108 cubic inch with cross sectional?
    Instead of standard 10’x10′
    (Note the columns will be multi directional that no subsequent parallel columns

  25. Hi.we are constructing for 1st floor have roof area near about 2800sq ft. And have total pillar 16(4pillars are 12*9 and 12pillars are 9*9) is it sufficient and one more thing Tata steel we are using but for roof how many mm of steel should use and for beam also kindly tell me pls

    • It is a very large structure. I request you to get detailed drawings from a qualified structural designer. You will get foundation designs, plinth beam designs, column designs, slab designs, staircase design. Please consult a qualified designer instead of risking it on your own.

  26. Hi, I am going to construct G+1 house in my land of 15×40 size. My constructor proposing 10 columns . 5 columns in one side and 5 columns in other side and he mentioned in between there is no columns is required because min distance between 2 columns is 15 ft. Can you give your suggestion. Is it safe if we don’t put any columns in between the 15 ft distance.

  27. My plot size is 50feet X 65feet,
    I want to built a cold storage Ground + 1 floor.
    RCC columns till plienth level are spaced at 13 feet on two sides & 25 feet at remaining two sides (periphery).
    There are also two columns at center line of 50ft side.
    Total 16 nos. columns.
    !st floor will have equally distributed load of 400 tons ( pulses bags) on 3250 sqft area.
    My question is what should be the size of ” I” beams & internal beams. Require drawing if possible

  28. sir, I have a work of common hall size20*15 with a gallery of 4*15. GF. +FF. Construction. In hall of 20*15 format there r 6 column of9″*9″ with 4-bar of 12 mm.size steel.In this we calculate 1600kg.steel for construction with footing, column,grond beam, Columbup to FF. slab. ,slab, lintel, weather she’d etc. Calculate. But after tendering party give design at time of ground beam. And total steel used by us is2915kg. I gave him in return to pay extra for steel. There is a dispute matter but I want to know I calculate steel is right. 1600kg for GF & FF.

  29. 1: What should be the column and beam size for G+2 25’X50′ house?
    2: If columns & beams sizes are same on 2nd floor as on G.F then how can we hide the projection of columns & beams on 2nd floor because we try to raise 4″ walls, especially partition walls?
    3: Can we use L shapes or T shaped columns in this house?

  30. 1: What should be the column and beam size for G+2 25’X50′ house?
    2: If columns & beams sizes are same on 2nd floor as on G.F then how can we hide the projection of columns & beams on 2nd floor because we try to raise 4″ walls, especially partition walls?
    3: Can we use L shapes or T shaped columns in this house?
    4: Can we use 4″x15″ columns on 2nd floor or what is the minimum size should be on 2nd floor?

  31. Dear Sir,
    I have planed to prepare G+1 house. My plot size is 12′ x 67′. So I request to you to give me advise the detail of slab, column, footing, beam, plinth and its steel members.

    • I had used 6″ columns in one of my G+1 projects a few years ago. I had to compensate by increasing the length of the columns to a minimum of 18″, and also ensure all internal walls were constructed of 6″ bricks instead of 4.5″.

      Please get appropriate structural design from your local engineers before constructing any building.

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