Calculating materials for your lintel

After foundation and oversite/German concrete, the next area of focus is lintel, when you have raised the block to the right level. Lintel is simply reffered to as a structural element that is used in course of construction usually at the top of windows and doors or other openings but below the roof which is also used to carry the load/ blocks that are placed on top thereafter. Lintel can be of different elements, but in our case we are taken the common concrete lintel for the purpose of discussion. The lintel concrete can be precast (cast with a model formed before placing or hoisting in right position) or cast insitu (cast on site as construction continues directly on top of blocks) The materials needed are granite, cement, sharpsand, wood and iron rods. To determine how a lintel will be placed, you have to consider the distance it has to cover by the door, windows or arcs, also you have to consider that the concrete will rest on some portion of blocks. For a concrete lintel space, half or one- third of the length can be used as the allowance where the lintel will spread to be able to easily rest on support and also carry the extra blocks coming on top . For a 900mm door for instance, is better for the total concrete lintel to be 1800mm, that is, 450mm allowances both sides. For most lintels, the iron rods will run as four in numbers usually 12mm rods are okay for this and the ones that forms rings around each lintel will be made of 10mm. The spacing of the rings can be from 150mm to 300mm but lets use 200mm as the average. To board this concrete lintel planks and 2 by 3 wood will also be needed so that it can carry the wet concrete mix that will be poured on it to form the lintel.   -Using the plan above as a sample to calculate the quantity of material needed for our concrete lintel. Due to lots of openings at the perimeter, we are going to run the lintel round the entire building as OPTION A, so to calculate the IRON RODS-

Add the entire perimeter -12.925m+12.925m+21.0m+21.0m=67.85m

For the doors let make each door of 0.9m as 1.8m i.e 0.45m overhangs for both sides that will rest on walls by the sides. 16 doors =16 x 1.8m=28.8m.

So total length for the lintel of the building is 67.85m+28.8m(doors)=96.65m Remember the 12mm iron rods which are the runners are four in numbers.

Therefore Multiply 96.65 by 4=386.6m Divide that by 12m which is the length of iron rods per piece in the market.

Total length for 12mm rod runner=386.6m/12=44 lengths/pieces of 12mm rods to buy  in the market.

For OPTION B- For the window lets take an average of 1.2 to be 2m for 13 windows =26 meters  (m for meters) For 0.6m window let make each 1m (plus the two sides overhang) For 8 windows=8m

So total length for the lintel of the building is 26m+8m+28.8m(doors)=62.8m Remember the 12mm iron rods which are the runners are four in numbers.

Therefore Multiply 62.8 by 4=251.2m Divide that by 12m which is the length of iron rods per piece in the market.

Total length for 12mm rod runner=251.2m/12=21 lengths/pieces of 12mm rods to buy  in the market.

For the rings, do not forget we are using spacing of 200mm interval (check image ‘a’) to know the numbers of rings required in OPTION A of  96.65m,

96.65m divide by 0.2m=483.25 rings .

For each ring the width and height of lintel is taken as size of block which is 225mm or 0.225m. So 0.225m x 4=0.9 ( Don’t forget there should be allowance for iron rods to cross over each other but is seen as negligible and ignored also the concrete poured should be able to cover the iron rods, hence the rings won’t necessarily be at 225mm length). 0.9 x 483.25 rings=435,  Then divide by 12 =36 lengths of 10mm iron rods.

FOR OPTION B

For the rings, do not forget we are using spacing of 200mm interval (check image ‘a’) to know the numbers of rings required in OPTION B of  62.8m lenght,

62.8m divide by 0.2m=314 rings .

For each ring the width and height of lintel is taken as size of block which is 225mm or 0.225m. So 0.225m x 4=0.9 ( Don’t forget there should be allowance for iron rods to cross over each other but is seen as negligible and ignored also the concrete poured should be able to cover the iron rods, hence the rings won’t necessarily be at 225mm length). 0.9 x 314 rings=283m,  Then divide by 12 =24 lengths of 10mm iron rods to buy in the market.

To calculate bags of cement, gravel/granite and sand- use volume 522.6 x 0.225 x 0.225 . Check these articles and also read the comments they are very useful. http://buildingcontractorsecrets.com/2011/07/how-to-calculate-the-numbers-of-bags-of-cement-in-the-foundation-of-a-simple-bungallow-from-a-building-plan/ http://buildingcontractorsecrets.com/2009/08/how-to-calculate-materials-in-concrete/

37 thoughts on “Calculating materials for your lintel

  1. Thank you for the knowledge being pass across. Kudos to you.

    Why did you consider taken the lintel round the building?
    I think doing that will put additional weight on the building.

    • Because of the closeness of openings round the building is better to run it round. The additional weight won’t count much but will actually help in the structural ability of the building.

    • 12 meters is the length of any iron rod in market so to know the numbers of iron rods to buy ,you divide the total length 2351 by 12.

  2. Pls check the number of stirrups reqd for this building again. I think that it was over calculated.

    The correct parameter to be used in calculating the number of stirrups is the total lenght of Lintel in the building which was calculated to be 130.65M divide by the stirrup spacing of 0.2M.

    To get a clearer picutre of my statement above, let assume that 130.65m is the length of one lintel which has 4 number 12mm bars in it, it therefore means that the stirrups will be tired at 0.2m
    interval along the length of the lintel which measure 130.65m

    But when we use the total length of 12mm. Bars in the lintel obtained by Multiplying the length of lintel by the number of 12mm bars in it(130.65×4=522.6m), it will be seen that the result has exceeded the length of the lintel itself and thus the number of rings will be over that which is required.

    So the right way of calculating the number of rings is:
    Lenth of lintel divided by ring spacing

    That is 130.65/0.2=653rings.

    Apart from this observation every other thing is OK

    Best Regards

  3. Pls how can i calculate for the total cost dat wl raise a 3 bedroom house,just from d foundation 2 d roof level. U cn pls use your initial plan.

  4. Since we are going to run the lintel round the entire building,where did you get additional 13 windows. to calculate the of 1.2 to be 2m for 13 windows =26 meters. And the one for 0.6m which is 8 windows too I think d beam runnig trough have taken care of all this window. Pls prove me wrong that Your calculation for the iron is wrong. nice job

  5. @Tosin,
    You are also correct. I was to do two options in my calculations but muddled it up, but it has been corrected in the article. Thanks I guess I am drinking too much of Pami these days…lol

  6. Weldone my oga, merry xmass n happy new year in advance. Yap! Pls i will need u to explain to me how to calculate for roof materials and its component like rafter on hip roof

  7. This site has become a dream site for every layman who is aspering to build a dream house at an affordable cost.your expo is wonderful. Thanks for the help.

  8. Well done sir.i cannot get d article.i just have a question.pls,where do u get 522.6 when u were calculating d no of bags of cement,granite and sand in d calculation over d lintel.i am not there to proof u wrong or right.Thanks.

  9. Weldone sir 4 d gr8 work u’ve being doing so far.,but u didn’t take Hooks and Cover into considerations when calculating the stirrup/Ring

  10. I am an engineer and has supervised lots of projects and still doing.Great work, for a 4BR flat- with granite not gravel, we finish to level (above lintel) with 1.5m and with 2.5m all carcass will be completed to roofing. You can build good quality house at reduced/low cost now which is what we do for our clients now. 08095679792

  11. pls how can I calculat d volum, of concrete, no of cement, sand, qraval nedded for column of 230*230*8.1

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