Rate Analysis for Brick Masonry

Analyzing the rate for brick masonry can easily be calculated by referring the use of material, labor and required tools for the work. Not only that but also the transport cost of materials and tools should be considered along the costing. To evaluate a more precise figure for these types of construction work are mainly influenced by the field experience rather than the theoretical knowledge.

Use of Material

The materials use for brick masonry work are;

       1.      Bricks

       2.      Cement

       3.      Sand

       4.      Water

 Bricks

There are different sizes of bricks available in the construction market. Generally, the most commonly used type of brick is the Engineering brick which is in the size of 215mm in length, 102.5mm in width and 65mm in height. The bricks using for masonry work should be kept in a water tub for few minutes and then store them in clean place till the skin of the bricks get dried. Washing out bricks in water help removing unwanted sand and dust from the surface of the bricks. When the bricks are too dry, it will absorb the water contained in the mortar which is not healthy for the strength of the mortar bond in masonry work.   

Mortar

Mortar is the mix of cement, sand and water. The ratios of mixing of these elements can result; different strengths of the bond with an appropriate workmanship. The manufacturers specification and guidelines given for the cement must be referred and execute it accordingly to obtain the maximum expected quality and the strength. The sand using for the mortar should be cleaned and should not include oil and mud in it. Because, if the sand is not clean, the formation of the bond of cement and sand with water will not be formed properly and will lead a weak bond with the bricks. The water that is used to mix the mortar should be portable water if not it restricts the mortar bond to be formed properly due to the mud, dust particles and dirt.

Rate Analysis 

Assume we have to construct a 10m long and 3m high brick wall using Engineering bricks with the stretcher bond and the thickness of the mortar bond to be 10mm. The ratio of mixing the cement and sand for the mortar is 1:5. Since, the transportation cost of materials and tools cost various with the location, we will not consider about that in this analysis. Note that water is available at the site. 
   

Stretcher Bond

Rate Analysis for 90m2

First, let us find the area of the brick masonry work contains 4 bricks. The height and width can be calculated as follows.
Height = 10mm + 65mm + 10mm + 65mm 
            = 150mm

Width  = 10mm + 215mm + 10mm + 215mm
            = 450mm

Area of the unit = Width x Height

                          = 150mm x 450mm

                          = 67500mm2

                          = 0.0675 m2

Therefore Nr of bricks per 1m2 = (1 m2  / 0.0675 m2) x 4Nos

                                                   = 14.82 x 4 Nos

                                                   = 14.82 x 4 Nos

                                                   = 59.23 Nos

Hence, the required amount of bricks = 90 x 59.23

                                                             = 5330.70 Nos

Add 5 % Wastage for Bricks               = 266.54 Nos

Total Required bricks say                     = 5597.00 Nos

Now let's find the volume of mortar required for the above work.

Volume of mortar in a unit = (0.0675m2 x 0.1025m) - (4 x 0.215m x 0.1025m x 0.065m)
                                            = 0.007 - 0.005 m3
                                            = 0.002 m3
Therefore total required volume of mortar for the above job = 0.002m3 x (90m2 / 0.0675m2)
                                      Total Required Volume of Mortar   = 2.67 m3

After finding the required volume of mortar, we can calculate the required amount of cement, sand and water for the job. How to calculate the cement and sand quantity in mortar is explained here.  

Required amount of sand per 1m3 of mortar = (1.66 x 5) / (1+5)

                                                                       = 8.3 / 6

                                                                       = 1.38 m3

Therefore, Total Sand required for the job    = 1.38 x 2.67 m3

                                                                       = 3.69 m3

Required amount of Cement per 1m3 of mortar = [(1.66 x 1) / (1+5)] / 0.0347

                                                                             =  7.97 bags (50kg)

Therefore, Total number of cement bags required = 7.97 x 1.38

                                                                                = 10.90

                                                                   Say       = 11 Cement Bags 

                                                           

Cost of Material

         Bricks = 5597 Nos @ Rs.13 = Rs. 72,761.00

         Cement = 11 Bag @ Rs.900 = Rs.   9,900.00

         Sand      = 3.69 m3 @ Rs. 3800 Rs. 14,022.00

Total Cost of Material = Rs.72,761.00 + Rs.9,900.00 + Rs.14,022.00

                                     = Rs. 96,683.00

Labor Requirement 

Assume that 1 Mason and 1 helper required 8 hours to construct a 10m2 area of the brick wall, then we can calculate the required amount of labor hours for the above job. 

Therefore required amount of Mason hours = (90 m2 / 10m2) x 8 Hrs

                                                                      = 72 Hrs

Required amount of unskilled/helper hours  = (90m2 / 10m2) x 8 Hrs

                                                                      = 72 Hrs

Labor Cost

Mason = 72hr x Rs.190/hr 

            = Rs.13,680.00

Helper = 72hr x Rs.140/hr

            = Rs.10,080.00

Total Cost of Labor =  Rs.13,680.00 + Rs.10,080.00

                                 = Rs.23,760.00

Assume Tools & Equipment Cost is 3% of total labor cost = Rs.712.80

Hence the Total Basic Cost of the above Job = Rs.96,683.00 + Rs.23,760.00 + Rs.712.80

                                                                        = Rs. 121,155.80

Rate for the above work without OH & Profit per 1m2 = Rs.121,155.80 / 90 m2

                                                            Rate per 1m2       = Rs.1346.18

                             

Note: These calculations are only applicable for brick walls in stretcher bond with the standard Engineering bricks.