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 refferedto as a structural element that isused in course of construction usually at the top of windows anddoors or other openings but below the roof which is also used to carry the load/ blocks that areplaced 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 ironrods. 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, isbetter 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 aroundeach 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, soto calculate the IRON RODS-

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

For the doors let make each doorof 0.9m as 1.8m i.e 0.45m overhangs for both sides that willrest 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 innumbers.

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 letstake 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 sidesoverhang) 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 innumbers.

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 knowthe 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 ironrods 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 knowthe 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 ironrods 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 divideby 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 .

# Calculating materials for your lintel

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