Minimum Standards for Structural Design | RCC Structures

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Thumb rules for Structural Design | RCC Structures

I highly recommend use of advanced structural design software like ETabs or Staad Pro for design of structures. This is very important. There are so many variables in design of a structure that no minimum standards can be accurate. This guide can be used for design of very small structures, maybe up to G+1 floors. But I would still recommend use of professional software. Every structural designer should learn these software. Use of manual methods is outdated. Manual method is only used for checks. Real design is done with the help of computers, with very advanced design concepts like pushover analysis, seismic analysis, wind loads simulation and many advanced methods.

You can hire me for your structural design need. Contact me.

Design of RCC Structural Components

In this article, I will discuss the minimum standards that can be followed for the design of RCC structural components of a structure, such as columns, beams, slab and foundation. We will also discuss the minimum safe standards for the reinforcing bars that are to be used for the design of the above mentioned Structural Components.

Minimum cross-sectional dimension for a Column: is  9″x 12″ (225 MM x 300 MM) which is the minimum recommended size. I have designed hundreds of buildings, and never had the misfortune of any structural component ever failing due to loads. I always use M20 grade concrete for construction, as it is the minimum recommended grade of concrete is IS 456:2000. Please don’t skimp on the quality of concrete. The minimum steel in a 9″ x 9″ column is 4 bars of 12 MM with stirrups of 8 MM steel rings at a distance of 150 MM centre to centre. In a 9″ x 12″ column, I add two more bars, to take the total to 6 bars of 12 MM diameter. This design can be safe for up to G+1 floors. But there are a lot of other factors involved.

Also check out:

Thumb rules for making a Column Layout

Construction on Site | Design of RCC Structures

Construction on Site | Design of RCC Structures[/caption]

Minimum RCC beam size should not be less than 9″x 9″ (225MM X 225MM), with an additional slab thickness of 125 MM. I generally use a minimum of 4 bars, with 2 bars of 12 MM thickness in the bottom of the beam, and 2 bars of 10 MM at the top of the beam. I maintain a concrete cover of 40 MM. I recommend use of M20 grade of concrete (1 part cement : 1.5 parts sand : 3 parts aggregate : 0.5 parts water).

Minimum thickness of RCC slab I recommend is 5″ (125MM) because a slab may contain electrical pipes embedded into them which could be 0.5″ or more for internal wiring, which effectively reduces slab depths at certain places, causing cracking, weakening and water leakage during rains. So, a minimum thickness of 5″ should be maintained.

Minimum size of foundation for a single storey of G+1 building, where soil safe bearing capacity is 30 tonnes per square meter, and the oncoming load on the column does not exceed 30 tonnes, a size of 1m x 1m should be used. Minimum depth of footing should be atleast 4′ below ground level. It is recommended to go to depths up to had strata.

Reinforcing bar details (minimum)

1. Columns: 4 bars of 12mm steel rods FE 500

2. Beams: 2 bars of 12 mm in the bottom and 2 bars of 10 mm on the top.

3. Slab

a) One Way Slab: Main Steel 8 MM bars @ 6″ C/C and Distribution Steel of 6 mm bars @ 6″ C/C

b) Two Way Slab: Main Steel 8 MM bars @ 5″ C/C and Distribution Steel of 8 mm bars @ 7″ C/C

4. Foundation: 6″ of PCC layer comes first. Over than, a tapered or rectangular footing of 12″ thickness is minimum. Steel mesh of 8 mm bars @ 6″ C/C should be laid. In a 1m X 1m footing, this would consist of 6 bars of 8 mm on both portions of the steel mesh.

148 thoughts on “Minimum Standards for Structural Design | RCC Structures”

  1. thanks a lot for the info because it helps us save from dubious consulting fees and it really helps us understand the real objective of construction design which is economy and feasibility.more power

    • Hello,
      We are glad that our articles have been helpful to you but it is to be remembered that you always consult a local Civil Engineer for the safe construction of your building. Gaining general knowledge about structures will prevent you from getting cheated but do not initiate the construction on the basis of your theoretical knowledge. An expert from the field of Structural Engineering has to be necessarily involved in the designing and construction of the building.

      • In my house the hall size is 14’x14′. It has beams from three sides of size 10″X10″ with 4″inside roof and 6″ hanging. The fourth side of hall has concealed beam consisting of four no. 12mm bar inside 4″ thick roof. Also this side has stairs meeting the roof. Is it safe or is their a need to reconstruct this fourth beam and how??

  3. Dear Benzu,

    I am very much impress from your articles like one in the link below:

    http://civilprojectsonline.com/civil-projects/minimum-standards-for-structural-design-rcc-structures/

    which seems to be a local project. I do prefab construction on a moderate scale which is not very popular here and therefore also want to diversify into RCC works. Can you please help me in providing structural engineering consultancy for my projects on professional bases? I live in Karachi Pakistan.

    Please let me know as soon as possible if you can help me.

    Regards,
    Darman Nayyer

  6. madam what should be the thickness of concrete in a foundation and the size of slab for G+2, as i read out that for G+1 a minimum size is 1mx1m and the thickness is about 15 inches is enough.

    • Hello Gautam,
      All these depend on structural calculations. The loading calculations are very important in this case. The structural design depends on the plan of the building to a large extent. The planning determines the loading conditions on the structure. After having calculated the loads, the quantity of concrete and steel is calculated.
      I suggest you consult a local Civil engineer before taking any step. However, I would like to share a good news with you. We are launching a new business website where people can get their structural design done at minimal rates without having to go through much trouble.

      Tc.

      • Good day benzu, I am on a project of residential building G+1 with a little pent house, on a 50ft by 100ft of plot my coloums are 9″ x 9″ of 4 bars of 16mm bars spacing between two columns is 10ft and 12ft. Presently now about constructing the slab +1 to be 5″ thickness, can I use 12mm bars for the beams? Thanks

  7. hello madam,
    i am in the process of construction of my house. please guide me regarding the depth of footing to be taken once the hard strata is reached.
    yoursuggestion is extremely valuable.
    thanks
    dr tushar date

    • Hello,
      Structural design is different for structures located in different places. It has to be done accordingly.
      I suggest you consult a local civil engineer for the purpose of Structural design and not do it yourself. This will ensure the safety of your house and your family.
      These articles are mainly for educational and knowledge purpose.
      I hope my suggestion will be taken into consideration by you.

      tc.

  8. Hello BenzuJK,
    I am writing you for my own house building and have some questions. I want to build 6 x 14 meters two-story RCC building with concrete Saltbox roof-slab of 4.5″ thickness and 15 columns for building joints. Building is residential with live load of about 750 lbs. please if possible tell me about the Minimum Standards for Structural Design of mentioned building because I am not able to pay for a local civil engineer and I will build mentioned building during 2-4 years to cover expenses for.

    Regards and Thanks,
    Basir
    From Afghanistan

    • There are no minimum standards that can be used. Total load on every column has to be calculated in order to design the column and its foundation.

      The load carrying capacity of a 9″x9″ column with 4 bars of 12 MM steel rods upto a height of 10′, with M15 concrete, is 30 Tons. That is the minimum, but in some practices, a minimum of 9″x12″ column is designed for slenderness ration factor. The design depends on a lot of factors, and is not black and white…

  9. Dear Benzu,
    I have been searching the net for some advice on structural design & it appears u can help me.
    I am trying to build a terrace garden on the roof of my 2nd floor flat in a area of 650 sq. ft.(total area of roof is 1500 sq. ft.). The columns are 10’x9”x15” (16mm-8 pcs & 8mm-4pcs steel), beams are 9″x16″ (16mm & 12mm steel) and the lintel is 125mm thick with 4″ & 5″ steel & is 4″ thick. All are RCC structures.
    I have got done the water proofing of the roof.
    My query is whether the roof can withstand load of 2″ of gravel + 2″ of stone crush sand + 8″ of soil and live load.
    I had consulted a few civil engineers who said yes it can but somehow they could not satisfy me with their reply.
    If u could guide me how to calculate the load bearing capacity of the structure and also please give tentative advice whether the structure can bear load (though i feel i am missing some information that u may require to calculate).
    Many thanks in advance.
    regards
    vijay

  12. Hi Benz!!
    I really find this site educative..I am a new bee in this field..I am now planning to construct a 2-storey residential house with rooftop..is my 25cmX25cm column with 4-20mm rebars is safe? Average distance between column is 3.5m..waiting for your valuable comment..thanks a lot.
    Sincerely..
    Abdul

  14. Hi
    I am a civil engineer and I am currently planning on constructing a G + 2 bungalow of 3138sq ft ( 1130+ 1258+750). I have done a trial pit for the foundation depth. there is 2 ft of black cotton soil and there after the strata changes to a brownish soil mixed with stones
    I will be doing soil testing in a lab.
    Can you advice me what is the safe bearing capacity required for a RCC framed structure, having columns and footings with slabs
    Thank You
    Bevin

  18. Dear Sir/Madam
    I am planning a double storey in 2200sft (GF~1400 and FF~800). Architect has given the following foundation: 20cm PCC bed concrete/60cm Rubble masonry (upto Ground)/then 45cm rubble masonry and 12cm Plinth beam RCC upto Plinth. Load bearing clay brick walls for super structure. The lintel beam is also of 12cm depth. My doubt is whether we should go for 15cm plinth beam and lintel beam instead of 12cm beams? Is 12cm sufficient or 15cm thickness better.
    The soil is lateritic
    Sincerely
    John Mathew

    • Hello John,

      I am not trained to design load bearing structures. So I wouldn’t know for sure. But bigger is always better, so you could use 15cm plinth and lintel beams instead of 12cm to be on the safe side.

  19. i have one industrial purpose shed and have 9*16 pillar (4+4)
    height is 18 feet and thay keep just steel roof no concrete slab now i want slab of 6 inch on it and want further one floor on it size of shed is 17*40 feet
    please do guide me if you reply i ask further more i like to ask about changes i need to do

  20. Thank you. Looking for some good aparment under construction, I located the multi-storeyed “Prestige Downtown” in progress in Vembuliamman koil street, West K.K. Nagar, Chennai. 78. The columns in superstructure have a uniform slender sectional dimention of 6”x24″ throughout. CMDA approved plans are not kept at site. Only, the builders plans for construction is available. i felt this is not in conformity with the Indian standards. i wish to be clarified on the following to enable me to proceed further:
    -Is it approved by CMDA?
    -has it been verified at site by CMDA?
    -are the set-back conditions as approved?
    -is check by CMDA on the dimentions and quality of construction happening as per norms?
    i shall be much obliged for a prompt reply.-

  21. Dear sir, i am constructing building of 1600 sq ft with 20 column ,maximum column distance is not more than 12 to 14 ft, for slab 01 eng is suggesting to use both side 8mm Tata rod & other is suggesting one side 10mm rod and other side 8mm rod, this is ground floor slab i want to make G+1 floor, can you inform me which one right.

    • What are the axial loads and bending moments acting on your columns? Please design according to that. Personally, in my designs, the minimum steel rods used are of 12 mm diameter. Strong columns are essential for the longevity of the building. Also, please hire good engineers who know what they are doing.

  24. Hello mam
    myself rahul i took land and its water logged area i want basement and ground floor to be constructed so what are the precautions should be taken before and after construction.

  27. I want to know about your site because i have to design the structure for my project which is an apartment.
    As I’m an architect i always need structural designers for my various projects.

    • Hello Ahmad,
      Since you are an architect, you do understand that civil engineering is a technical field. It is always recommended that we get our homes designed by civil engineers in order to avoid structural instability that might result.
      I am an Architect and a planner. I have Civil engineers in my team which is why I understand the complexities of structural design. Although there are projects which I can do myself, I still prefer getting it done by structural engineers. It just gives me 100% confidence that this cannot go wrong. Do get in touch if you ever need help.

      Kind regards,

  28. How much quantity of 16mm and 12 mm steel rods ( indus make ) required for 8″ x 18″ column for 4 story commercial building.
    pl reply for my email

  29. My residential construction is going on. In our building Column beam is closed in ground floor and our engineer advice us for first floor Column beam is not required. Is it advisable one?

  30. My residential construction is going on. In our building Column beam is closed in ground floor and our engineer advice us for first floor Column beam is not required. Is it advisable one?

    Thanks
    Durairaj. G

  33. Sir, I just started my construction project occupying a surface area of 13 * 19= 247sqm. G+1…The upper floor is comprised of four studios ( each is made of a sitting room, bed-room,kitchen and toilet). The columns are 30 ( supporting pillars) and 4 veranda pillars for the ground floor ( total of 34). Each column is 9*9 inches containing 6 10mm steel rods. Foundation on a dry area with foundation blocks filled with mortar and all foundation edges bound together with 10mm steel rods. Advice if the design is solid enough to withstand adverse conditions. Thanks.

  34. Hi, Sir/ Madam.

    Thank you for shearing valuable information. I am planing to build a G+1 store in 1400 sq ft as of now but in future will add a another floor as well, my Civil engineer has given me the mix design of column 12mm, 10mm and 8mm rods will be used for column, will that be good enough. Or i will as him to use 16mm all sides. My budget for construction is 30 lakhs, what can be done by that, Only construction ? I ask for stainless steel railing, a balcony, a small sit out in trace, inbuilt Led lights, and one tub for kids, Engineer is charging me extra for that. what does the 30 lakhs will do. please help me out.

    Thank you.
    Anto

  36. Hi Benzu,

    Thanks for the valuable information which is very very helpful for individuals like me. It helps me to evaluate the structural design given by my architect is as per standards or not. I am constructing a G+2 Building in 30*50 site. The distance between the columns is 26 feet and my architect suggested to use 9*15 columns. Can you please let me know if that is fine and how far is it safe? Thanks for your time………
    Regards,
    Ravi

  38. I have a house with 29 pillars (plus 2 brick pillars) of 9″x12″ spread over an area of approx 3200 sft in an hilly area. The roof height on the ground floor is 10 sft. I wanted to increase the column height (more than 10 ft) for the roof on first floor. What is the maximum safe floor height for the building?

    • It is good that the columns are rectangular, so you avoid the problems that come with slender columns. Use stronger concrete, something like M25 strength concrete for columns, and you could go to 15′ without issues.

  41. Sir, I constructed g + 2 floors in 1200 sqft. area. in 2nd floor in between colums of 13 feet, they used concealed beam in RCC slabs itself and surrounded by bricks wall ( i.e. East to west is 28 feet and followed by 3 coumns and surrounded by brick walls for last 2 columns) and from Centre columns to the last coumns, they adopted concealed beams and above the concealed beams we constructed one room also. can u pls tell me, concealed beam will take a load bearing.

  42. hello mam

    i have newly constructed small bunglow… in the slabs we have used 8mm bars at 6 – 7″cc … is this enough for the slabs?

    and second question is my porch aria slabs is at bottom level of the beam so for the leveling we have filled this area with Brickbat coba around 10″ depth…. is this will over load to the slab or is it ok?

    pls consult about is

    thanks
    yashwant

  45. You must have to read the requirements in the building code. Take note of the minimum size of re-bars to be used. In a country like the Philippines, where earthquake is a natural calamity and phenomenon expected..then you have to level – up your design. better consult a civil/structural engineers. Dead loads, live loads and even moving loads ( horizontal and vertical) must have to be keenly considered in coming up with you RCCs.

  47. hi benzuJK
    im planning to build a 3 storey house.ground floor a shop/store next floor and last would be a house..i ask for a foreman he suggest to use 12mmx6pcs steel rod for foundation..8 foundations for the GF. the rest of the steel rod is 10mm..what can you suggest for a better/secure foundation and size of an steel rod to be used? i ask sonce i dont have knowledge for construction of the house..
    thanks

  48. Hi,
    we need your help you can tell me about 70 tons load beared RCC Flooring how much design PCC 1:4:8 thickness, RCC 1:2:4 Thickness & Steel bars spacing, kindly suggest me.

    Regards,

  49. Hi Benzu,

    I got my buolding built by a contractor who did not seem to have consulted a structural or a civil engineer. The dimension of the hall is 32X33 feet. He has raised de walls with three concrete belts one at de foundation, second at de lindal level (7 ft) and 3rd at de roof level. There are no columns in de design. There are 4 big 32 ft long beams across de hall , so distance between each beam is 10 ft. 2 beams r built top of de end walls and hence dey look supported by de walls. The other 2 beams in de centre are landed on the sidewalls. There is no columns in between. Now my friends r saying columns (pillars) are mandatorily required to support the load. The buiding has ground floor only and I dont wish to build any more floors on top of this.
    1)Is it true that de said brickwalls cant withstand de load even though there are concrete belts at three levels?
    2) Some frends r suggesting to build pillars outside de building to support the beams. Is it necessary?
    3) will it help to have a column in de centre of de beam to support the load?

    • This is a complete disaster. Why did you not consult a structural engineer? This is extremely dangerous. I can not really advise you over an email or a message. You need to immediately seek help from a certified civil/structural engineer and get the problem sorted.

    • Hey I don’t know about your complete building design but for your notice they’re actually two kind of building construction. One is the load bearing type and the other one is framed structures. Framed structures, like the name itself is a bonded frame between beams and columns. The foundation of the same will be the column footing and plinth consist of a tie beam along all the columns. In this type of construction all loads of the slab are transferred to the beams, which are again transfered to the columns and dispersed into the footing. This kind of construction is much safer than load bearing structures when it comes to g+2 types of buildings. Also in this the walls generally fulfill the purpose of protection and partition of rooms from external and internal disturbances. There’s no other role for the walls.

      But when it comes to load bearing walls, all the loads from slabs and beams are tranfered to the walls only. No columns are mostly required, in some cases for very long beams and heights support pillars or brick columns are provided. Also the load from brick walls are transferred to the foundation, foundation maybe of Random rubble masonry. So you don’t need to be worry about the things. But it will be better if you consult a licensed Civil Engineer (structural) to nullify your worries. Have a great day!

      • Thanks a lot for the advice, my question is, the column of my house is 6nos.of 12mm of 12″*12″, the foundation too is also 12mm mesh is of depth 5′, i am planning g+2 with acc block wall from 1st floor upwards and the top floor of steel frame alongwith gcc roofing, is it enough and i am also planning for lintel provision in all floors, i am from manipur which is earthquake zone-v, could you suggest steel size and number in beams etc

  52. i want to construct a G+3 building in a plot size of 38×33 sq.feet for class room purpose havind diamention of 33feet×35feet and i didn’t want to give any pillers in between. please suggest the size and number of pillers and beams in this structure.

    • Hi Abhishek,

      Structural design depends on the location, soil and the design of the building. It is therefore not possible to answer this question. It would be best for you consult a structural engineer.

  53. I am constructing my house now with a 12mm steel and column depth is 6 feet. now I plan to increase the height from plinth beam to lintel height from basement to 10 feet, due to increase the floor level 3 feet from PB/
    it looks PB to floor 3 feet and the lintel from PB 10 feet and from PB to ceiling 13 feet, it is safe to construct.?

  54. I am building a house of size 1400 sqft. with load bearing walls and rcc roof. As per building codes in my area rcc foundation belt above rubble foundation and rcc lintel band are must. One engineer suggested that adding one additional rcc band just like lintel band below the window level called still band will give added protection in case of earthquake. Is it true?

    • Hello Nazir,

      There are thumb rules for designing buildings. Every building requires a unique structural design. I would strongly recommend you to hire a certified structural engineer. This is not something to be done by a lay person. Let me know and I will direct you to our paid design service.

  56. Dear Sir,
    i am planning to G=1 Building total 750 Sq.ft.
    COLUMNS
    square column size 9″x9″ (14 square columns) reinforcement 4 nos of 12mm and 8mm Ties. circular column 9″ dia (4 circular columns for portico) reinf. 6 nos of 12mm and 8mm Ties. (1:1.5:3)
    BEAMS,
    All are Square beams size is 9″x9″ Reinf. 4 nos of 12mm top and bottom (2 top and 2 bottom) and stirrups 8mm (1:1.5:3)
    SLAB,
    We fellow two way slab thick 5″ reinf. 8mm @ 5″ and 8mm @ 7″ spacing

  61. Respected sir
    I am constructing G+2 FLOOR.1400 Sq ft area having 16 columns sizing 10 x 15 ” ( 4 x 12 mm and 2 x 16mm iron rod)
    Plinth Tie beam Size 10 x 12 “(4 x 12 mm )
    Lintel tie beam size 10 x 10 “(4 x 12 mm ) as per architect
    kindly advise is it sufficient ?
    regards rituraj utkarsh

  62. Hlo sir all the details are very very useful for me.i have a big doupt .can u clear me pls. For example i want to design a small building how to design each part of rcc for slab to foundation and how to calculate loads.

  65. I am constructing a new house G+1 in which lobby size is 37×23 feet . Is it possible to put flat beams instead of normal beam . If yes what will be the size of beam and how many beams to be put into RCC slab with distance.

  66. I want to ask u that i want to make a hall of 24 ft by 29feet ..the length of beam between two pillars is 29 feet …what should be the size of a beam and what will be the width of iron rod and how many iron rods are used?

  67. Hi I want to build a hall with area of 55 ft long and 45 feet wide and I don’t want collume between hall so how much collumes are required and with what size of it ??

  68. Sir/Madam, I want to extend my Chajja/Loft by 3ft towards the compound and I’ve put 3 columns with distance of 15 feet . The existing Chajja is of 2ft width and 25 ft length. The 3 columns are of 6″*6″ with a finishing of 9″. Is it OK if I go for a beam of 9″*9″ of 16 mm rods at the top and 12 mm rods at the bottom?

  69. Sir/Madam, I want to extend my Chajja/Loft by 3ft towards the compound and I’ve put 3 columns with distance of 15 feet . The existing Chajja is of 2ft width and 25 ft length. The 3 columns are of 6″*6″ with a finishing of 9″. Is it OK if I go for a beam of 9″*9″ of 16 mm rods at the top and 12 mm rods at the bottom? And how many rods I’ve to use for top and bottom?

  70. Dear sir/madam, can you tell me the load carrying capacity of 10″*10″ square column with 6# of 16mm rod, but the concrete mix ratio is just 1:3:6(M10). Thanks in advance..

  71. Madam…..Can i use Your Given Dimensions of Columns,beams,Slabs and Foundation For G+1 Building.Provided that the Soil present is purely Sand .And i m not sure that the concrete will be properly Handled.Please do tell me the depth of foundation and center to center distance between successive columns.
    Regards and respect.

  72. hai sir this is aravind. i am a civil engineer. now my 1st project is going on. i am design the 1st lift column 225mm x 225mm the footing size is 4 x 4. each dirction the columns are placed in the distance of 10 feet c /c is it safe or not for g+1 story plz rply…..

  73. hello …i observed number of sites in which engineer used a column of six inches width and other dimension as 18 inches …am also civil engineer but never seen such columns used what ur comment about

    • They might use it in rare cases, but generally I would avoid it. I have used 6″ columns and beams in lift wells and staircases, where I am forced to use 6″ walls, and cannot afford a 3″ column or beam projection into the limited staircase area. But if there is space, I never go below 9″ width.

  74. Hello

    i am constructing G+1 House , Area plot size is 25 Feet X 62Feet & construction place are 20.7″X54.5″.

    Total column 18 Number, each one column distance 10 feet and below, i am using 12 mm bar 8 Number for each column, can you reply , is it enough?

    Regards
    mohamed Hanifa

  75. My house(20ft by 45 ft) have G+1 floors and have 4 columns of 9 inch by 12 inch having two 16mm bar + four 12 mm bar.
    Beam of 9 by 9 having 12mm and 10mm bar and 6 inch thick slab.

    Is this construction good?

  76. Dear Sir,
    I have made my house. it is parking + 3 floors. It is made in 1800 sqft. it is built on 17 coloumns. 11 columns are 15×9″ and rest 6 coloumns are 9×9″. The concret mix used in coloumns, beams and slabs are 1:1.5:2.5. Also the balconies are 31feet length and width 6 feet without any support or beam. is the balconies safe ? please reply me. some friends say i should put coloumns under the balconies. is it really required.

  77. Hi,
    Is it safe column size of 250 x 350 with 6no 12mm rod for g-2 building??
    Please share your mail id as I would like to share the foundation drawing with you.

  78. Dear sir/madam,
    We r designing for g+1 building residential and have total area 158sqmtr and slab near about 3000sq ft and total pillars 22 at 11 ya 10ft distance some r 12*9 and sm r 9*9 inches) and beam 12mm. Kindly tell me is it safe construction?

  79. BenzuJK :
    I would suggest you to hire a certified civil engineer for the job.

    Can u please help me.

    Im constructing a g+2 building in red clay area, the plinth area is 1450 sft. My contractor told that he is using 12mm 10 mm and 8 mm steel rods for foundation and taking depth of 7 feet. if in the future shall we build 2 more floors on this, kindly suggest immediately please.

  80. New construction g+2 10″ x10″ columns and beams M 20 4 -12mm and 2-10mm tmt rebars base plate and RCC plinth 5′ height 5″ thickness aligned with a tie beam
    Up to floor level columns aligned with tie beam would rest on a reverse base plate (floor leval) embossed by a steel sheet and separated by a steel sheet embossed column bottom and the corner of the superstructure will be designed to allow movement of the superstructure by 6″ then restricted to isolate seismic energy flowing into the structure the metal sheets is used with a view to reduce friction the structure would be g+2 dimensions 20’x 48′ spacing and span 12 &10′ request advice if I should go ahead with this innovative idea remember our zone is highly earthquake prone it is no doubt that it would be somwhere around 7.5 to 8 Richter scale as the structure will not be anchored is there a chance of toppling ?

    • I would recommend you get the design from a professional structural designer. It is dangerous to take risk in high earthquake prone regions. You can get a good structural designer at around Rs 5 per square feet. It is worth it.

  81. Hai my plot size is 22×39 and engineer plan for g+1 column size 12″ ×9″ and rod is 12mm×6 No’s for 15 no column and ground beam size 15″ ×9″ and rod is top is 3×12mm bottom is 3x16mm it is OK or modify help me

    • Depends on the area of the slab. In most of my projects, I use 5″ thick slabs. Minimum steel is 8MM @ 150 MM C/C. For larger slabs, my calculations lead me to increase steel to 10 MM bars. Sometimes, I even have to go to 5.5″ or 6″ slab thickness, but it is very rare.

  83. Hai sir
    I am a civil engineer I constructed the house 516.5 sqft. 7nos of 9″x9″ pillar having 4 nos of 12 mm and 2nos of 9″x1′ columns with 4 nos of 12mm and Middle of column is 2 nos of 10mm the footing dimension 4’*4’*1′ and it is 6.5 feet below the ground level. Corner 1pillar is located on the one side because of some place problems. The distance between these columns are in x direction is 9’and in y direction is 12’and 11′ ,8.5′ now I have a plan to construct one more floor that is g+1 is it safe whether it’s is not safe please gives the reinforcement details.

    (Note:I provide 1′ of plinth beam 3″of sill and 1’of lintel lintel same as plinth beam and all the beams are L crinked and All footings having 4″ L crinked.1st lift column is same as super structure )

  84. Just want to ask.i built my house step by step.my mason made 11 column for 2 storey house.each column has 6 16mm RSB with a ring of 10 mm.is it safe column?for 2 storey house?

    • There are a lot of unknowns. It would have been better to get structural analysis done by a professional engineer to be sure. It can even save money, as you can prevent over-engineering in your structural elements too.

    • Depends on the span, imposed loads, point loads. I have used 150mm beams in a few locations in my projects, but only in very rare instances where 230mm beam would be a problem. I would not recommend it.

  88. Nice work sir, would you take the trouble of stating the size of steel in beam and column in g+2 with gc sheet roof and distance between column is 13 and 10ft in zone4 and 5 as i am planning for it

  89. Sir for g +1 roof building I used 8mm steel mesh in footing with 2 to 3 inch spacing for 3 X 3 ft footing keeping in order to avaio punching shear possiblity , soil there has ample amount of bearing capacity ….is it safe …although I stand pro recommend 6 mm steel mesh

  91. Sir, I”m planning for g+2 with acc block wall from 1st floor upwards with steel roof structure with gcc sheet, some portion of ground floor were completed with 12″*12″ column – 6pcs 12mm with space of 13′ and 10′, footing depth of 5′ depth with 12mm mesh and beam still not constructed, earlier by parents. So I request you to inform whether the said parameters are enough or not, and instead of pulling it down, use of lintel and strong beam will suffice. I feel little worried as people I consulted have different opinion and I am from Manipur which is under earthquake z-v.

  92. hi,
    I’m an architecture student
    my current project is an apartment complex. My design is somewhat hexagonal
    I ended up having a lot of columns here and there
    now there is no space in the still floor for car parking
    is there anyway I can rectify this or if I go for basement level parking the how to increase the span for free movement of cars?

  93. Hi Sir. I made G+1 house, 15.0 meters by 12.0 meters house dimension, my column is 250mm x 250mm with 8 bars (4nos. 12mm, 4 nos. 10mm) with stirrups 10mm (ties 1-50mm,3-100mm, rest 150mm @ C.C), with CHB thickness 5″, and my slab thickness is 5″. My footings is 1.5meters below ground level (1mx1mx200mm) and pedestal 250x250mm. is this safe?? thank so much in advance for you response.

  94. Hi Sir, I made a 15meters by 12meters house, with 17 column 250x250mm in span of 3 meters each.
    Column 250×250
    Column rebar 8 nos. (4-12mm,4-10mm), stirrups 10mm (ties @ 1-50mm,3-100mm, rest 150mm)
    Slab thickness 125mm
    Footing 1mx1mx100mm (1.5meter below ground level)

    is this safe sir? thank you so much in advance for your response.

  95. our contractor while constructing 3rd floor slab roof of a proposed 6 storied building mistakenly use in ratio of 1:2.5:3:5 of concrete while doing 6.75 ” inch slab. is it safe ?

  96. It is the design calculation result who will tell you the sizes of the columns or beams and the rebars to be used for your building to be constructed. However, if you are in hurry (so long as you’ve a background or graduate of civil engineering, then no need to hire an structural engineer to help you design you house), just assume, by trial & error, the sizes of structural frames and rebars, e.g.: column, beam, and etc… and do the calculation via “investigation” method until you reached the conclusion, “safe”.

  97. For the stirrups/ties, the ACI code 318 limit the sizes; 10 mm. dia.for rebars 32mm.φ.or.smaller, and 12mm. dia. in size for 36mm φ to 57mm φ and bundled longitudinal bars. There are also limit for stirrups spacing for beam, for the first stirrup is 2″ or not more than d/4 from the face of the support, while the remaining shall not go beyond: Smax=d/2. For ties (column) spacing shall not go beyond the Rule of thumb, least dimension of the column, which shall be d/2 (max ties spacing), Where, d, is the least dimension. But as per the ACI 318, the ties spacing is depend on the sizes of the vertical bars, column, and ties. For Specified Concrete strength f’c shall not be less than 3000 Psi (20 Mpa), for lightweight aggregate concrete shall not exceed 4000 Psi (30 Mpa).

  98. Hi I want to know if it is safe if my columns are 250mm x 300mm with 6 -12mm rebar and my beam is 250mm by 300mm with 2-12mm on top and 4-12mm on bottom for a 8m x 5.6m G+1 house?

  99. Hello,
    First floor room is under construction with a span of 20x10feet which consist of a mezzanine (7ft).
    Double height one at 10ft for the span of 7x 10ft and another of 15ft with span of 14x10ft is done.

    The RCC ceiling thickness for the 10ft height was kept at 5” and for the 15ft , I had suggested 6”.

    I am worried that 6” RCC ceiling is more. Is it ok ? Steel reinforced with 6” with using 8,10 and 12mm. Also have a beam at 14feet.

    Kindly suggest.

    • Recently I had used a 6″ slab, but it was a peculiar situation, a 6 feet long cantilever slab.

      Generally, a 5″ slab is sufficient in 90% of the situations.

      In your case, you could use a 5″ thick slab for the span of 20′ x 10′. But you have to take care of the beams.

      It would be always better to use professional help in such situations.

  100. Sir, I’m structural engineer student. I’m so much glad and impressed about to these golden thumb rules. Thank you very much for your contribution towards civil engineering. Moreover, sir please email me any educational materials as relate civil engineering.

    • M15 is the grade of concrete with final compressive strength of 15 MPa.

      Grade of concrete generally shows concrete’s 30 day compressive strength in megapascals (MPa).

      RCC means Reinforced Cement Concrete, which means concrete which has been strengthened by reinforcing it with steel (or other materials having high tensile strength), because concrete has good compressive strength, but very low tensile strength.

  105. i hav built a single storey house, the soil under the footing is loose fine sand, i used a 30cm thickness footing of 1m x 1m with rebars of 10 16mm c/c, a column of 9″x9″ with 8 12mm, with plinth beams and tie beams at upper parts of the columns. Any comments suggestions with these? Thanks

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