A lot of people embark on building houses without sufficient knowledge of the quantity of materials required for the house to be built.In their ignorance,they are left entirely at the mercy of the contractor.So,it is important you are knowledgeable of the quantities to buy so you are not cheated.The aim of this thread therefore,is to help those intending to build improve their knowledge of estimating building materials.

BLOCK MAKING:
The materials for block making are cement and sharp sand and the standard mix is in the ratio of 1:6(1 bag of cement to 12 headpans of sand).The quantity of blocks per bag can be increased by changing the mix i.e using more sand and less cement,thus:
*1:8(1 bag of cement to 16 headpans of sand)

*1:10(1 bag of cement to 20 headpans of sand)

*1:12(1 bag of cement to 24 headpans of sand)

The approximate quantity of blocks per bag per mix are:

1)1:6 = 19-20 blocks(6" ),13 blocks(9" )
2)1:8 = 25-26 blocks(6" ),17 blocks(9" )
3)1:10= 32-33 blocks(6" ),21-22 blocks(9" )
4)1:12= 38-40 blocks(6" ),25-26 blocks(9" )

Whichever mix you choose,bear in mind that the more the sand the weaker the blocks and less secure your house could become.

Note:
A trip or tipper of sand(135 cu.ft) contains 216 headpans of sand.
A trip or tipper of sand in 1:8 mix = 338 blocks(6" )

CEMENT:
Assuming your house requires 2000 (6" )blocks to build,using 1:8 mix the bags of cement required will be:

From (2) above
25 blocks require one bag of cement
2000 blocks will require 2000/25 =80 bags

SAND:
Recall (from above)
338 blocks require 1 trip
2000 blocks will require 2000/338 =5.9
(approx. to 6 trips of sand)

QED.

***A trip may be less than 135 cu.ft.