All about civil construction knowledge- PARAM VISIONS

Calculating the cost of stone (random rubble) masonry work./Rate analysis of random rubble (stone )masonry work.

 Let us consider RR ( stone ) masonry wall for the calculation purpose as shown in the below drawing.

Given data:

Length of the stone masonry wall = 15 ft.

Height of the stone masonry wall = 7 ft.

The thickness of the RR masonry wall = 1.5 ft.


The total volume of the RR masonry wall

= [length × height × thickness]

= [15 ft. × 7 ft. × 1.5 ft.]

= 157.5 cu ft.


Before proceeding further, go through the article 👇

👀 . What is random rubble masonry? - Thumb rules in RR masonry calculations. 

to understand the calculation procedure without any questions.


A. Material calculation:

1.  Volume of  rubble stone:

The required vol. of stone 

= [1.25 × the vol. of RR masonry wall]

= [1.25 × 157.5 cu ft.]

= 196.875 cu ft.


2. Cement mortar:

The required dry vol. of cement mortar

= 40% of the vol. of RR masonry.

= [40 × 157.5 cu.ft. ÷ 100]

= 63 cu ft.


Let us build this wall in the cement mortar of a 1:6 ratio 

 a.  The volume of the sand

         = [{its ratio  ÷ ( total ratio)} × dry mortar vol.]

          = [{6  ÷ ( 6 + 1)} × 63]

           = [0.8571 × 63]

           = 54 cu ft.   or 

         = 1.53 cum.


b. Volume of the cement 

   = [total dry mortar vol. - volume of sand]

    = [63 cu ft. - 54 cu ft.]

    = 9 cu ft.

As you know, one bag of cement = 1.226 cu ft.

  Number of cement bags 

    = [9 cu ft. ÷ 1.226 cu ft.]

    =   7.34 bags.


B.  Labor calculation:

The labor rate per cu ft. of the RR masonry work ranges from INR 10/- to 16/- depending upon the region.

Let us consider an average rate of INR 13/- per cu ft.

The total cost of labor for RR masonry

   = total vol. of RR masonry in cu ft.  × labor rate/ cu ft.

   = 157.5 cu ft. × 13/-

   = INR 2,047.5/-


To go through rate analysis & cost-related articles, click here.


Now, let us calculate the total cost of RR masonry in table format.

Sl. no.

Item.

Qty.

Rate.

in INR.

Unit.

Cost

in INR.

1.

Rubble stone

 196.88

        35/-

Cu ft.

   6,890.80

2.

Cement

     7.34

   380/-

bag

   2,789.20

3.

Sand

   54.00

   60/-

Cu ft.

    3,240.00

4.

Curing

Lump-sum

        200.00

5.

Miscellaneous

Lump-sum

        275.00

6.

                                                      The material cost =

  13,395.00

7.

                                                       Add 5% wastage =

        669.75

8.

                                                   Total material cost =

  14,064.75

9.

                                                                Labour cost =

      2047.50

10.

    The total cost of RR masonry wall =

   16,112.25

 

Note: To get accurate results, insert your regional market rate of materials & labor, in the above table.


a. The cost of random rubble masonry/cu ft.

= [total RR masonry cost ÷ total masonry vol. in cu ft.]

= [16,112.25 ÷ 157.5]

= INR 102.30 /cu ft.


b. The cost of random rubble masonry/cum.

   = [102.3 × 35.3147]

  = INR 3,612.70 / cum.

( As 1cum = 35.3147 cu ft.)


Note:

 If the work is handed over to any contractor, you have to add 10% extra for his profit.


Thank you for going through this article. Have a good day😄.

If you have any queries, you can ask me in the comment box👇.



Share:

No comments:

Post a Comment

Translate

Blog Archive

popular posts

Recent Posts

Google search