Plastering calculation method

CALCULATION OF QUANTITY OF MORTAR AND QUANTITY OF MATERIAL REQUIRED FOR THE PREPAIRATION OF MORTAR

      The quantity of mortar for a uniform surface shall be obtained by multiplying the thick of the plaster and the total area to be plastered (Area × Thickness). But for filling up the joints and to make up the un-uniformity of the surface the quantity may be increased by 30% of the quantity of mortar required for a uniform surface.

      To obtain the total dry volume of constituent materials or mortar the wet volume may further increased 25%.

FOR THE CALCULATION WE CONSIDERING 12MM THICK PLASTER FOR 100 SQM. WALL AREA

QUANTITY OF MORTAR:

To obtain –

      Quantity of Mortar for wet mix of uniform layer = (12/1000) × 100 = 1.2 Cum.

      Adding 30% to fill up joints and uneven surface etc., the Quantity of Mortar for wet mix = [1.2 + (1.2×30%)] = 1.56 Cum.

      Again adding 25% for the total dry volume = [1.56 + (1.56 × 25%)] = 1.95 Cum.; Says  2.0 cum

QUANTITY OF MATERIAL:

To obtain, considering 1:6 cement sand mortar.

      Dry volume of mortar = 2.0 cum

       Cement: Sand = 1:6

       Cement + Sand = 1 + 6 = 7

       For Cement –

      For Sand –

SIMILARLY, MATERILA FOR 20MM THICK PLATERING OF 100SQM WALL AREA

QUANTITY OF MORTAR:

To obtain –

      Quantity of Mortar for wet mix of uniform layer = (20/1000) × 100 = 2.0 Cum.

      As the thickness of the plaster is more, so in case of 20mm thick plastering adding 20% to fill up joints and uneven surface etc., the Quantity of Mortar for wet mix = [2.0 + (2.0×20%)] = 2.40 Cum.

      Again adding 25% for the total dry volume = [2.40 + (2.40 × 25%)] = 3.0 Cum.

QUANTITY OF MATERIAL:

To obtain, considering 1:6 cement sand mortar.

      Dry volume of mortar = 3.0 cum

       Cement: Sand = 1:6

       Cement + Sand = 1 + 6 = 7

       For Cement –

      For Sand - 

CALCULATIONS FOR RICH MORTAR PLASTERING:

      Rich Mortar Plastering generally used for R.C.C Roof ceiling.

      The quantities of material will be less for rich mortar plastering because the use of cement quantity will be more then the quantities of other material, so the voids in sand and the reduction in volume of dry mortar will be less.

 FOR THE CALCULATION WE CONSIDERING 12MM THICK PLASTERING OF 100 SQM. WALL AREA FOR R.C.C CEILING:

QUANTITY OF MORTAR:

To obtain –

      Quantity of Mortar for wet mix of uniform layer = (12/1000) × 100 = 1.2 Cum.

      In case of R.C.C ceiling plastering the unevenness of surface will be less, so considering  20% for the un-uniform surface, the Quantity of Mortar for wet mix = [1.2 + (1.2×20%)] = 1.44 Cum.

      Again adding 25% for the total dry volume = [1.44 + (1.44 × 25%)] = 1.80 Cum.

QUANTITY OF MATERIAL:

To obtain, considering 1:4 cement sand mortar (generally 1:3 to 1:4 considered for R.C.C ceiling plastering.

      Dry volume of mortar = 1.80 cum

       Cement: Sand = 1:4

       Cement + Sand = 1 + 4 = 5

       For Cement –

      For Sand –

SIMILARLY, MATERILA FOR 6MM THICK PLATERING OF 100 SQM WALL AREA FOR R.C.C CEILING:

QUANTITY OF MORTAR:

To obtain –

      Quantity of Mortar for wet mix of uniform layer = (6/1000) × 100 = 0.6 Cum.

      In case of R.C.C ceiling plastering the unevenness of surface will be less, so considering  20% for the un-uniform surface, the Quantity of Mortar for wet mix = [0.6 + (0.6×20%)] = 0.72 Cum.

      Again adding 25% for the total dry volume = [0.72 + (0.72 × 25%)] = 0.9 Cum. Says 1.0 cum

      Generally in practice for 6mm thick plastering of R.C.C ceiling the quantity of dry volume of mortar may be considered as 1.0 cum.

QUANTITY OF MATERIAL:

To obtain, considering 1:4 cement sand mortar.

      Dry volume of mortar = 1.0 cum

       Cement: Sand = 1:4

       Cement + Sand = 1 + 4 = 5

       For Cement –

      For Sand –

FOR NEAT CEMENT FLOORING:

      The neat cement finishing, in floor, dado, or skirting, the thickness of the cement layer over the finished uniform surface may be taken as 1.5mm (1/6”) thick.

To calculate the quantity of cement considering a uniform floor area of 100 Sqm with 1.5mm thick cement finishing –

      Quantity of cement paste = (1.5/1000) × 100 = 0.15 Cum.

      Adding 25% for the total dry volume = [0.15 + (0.15 × 25%)] = 0.187 Cum. Says 0.19 Cum.

      Considering 1 cum of cement = 1600 kg, for 0.19 cum = 0.19 × 1600 = 304 kg = 6.08 Bags Says 6 bags.

      For neat cement finishing of 100 Sqm. floor areas with thickness of 1.5mm 6 bags of cement required.