HOW TO CALCULATE CEMENT, SAND QUANTITY FOR PLASTERING?

HOW TO CALCULATE CEMENT, SAND QUANTITY FOR PLASTERING?
                   Following points should be remembered while calculating the quantity of cement, sand for plastering work.

1. For wall plastering:
Cement : Sand = 1 : 6

2. For ceiling plastering:
Cement : Sand = 1 : 4

3. Thickness of plaster should be in between 12-15 mm. If an additional coat is required then do not do it at one go.

4. Use good quality of cement & Sand.

5. Use measuring box (not head pan) for site mix.

We will calculate cement and sand for 100sq.m plastering area in 1:6 ratio and thickness of 12 mm.

Cement Mortar Required:

Plastering thickness = 12 mm
= 12/1000 = 0.012m

Volume of cement mortar required = ( Plastering Area x thickness )
= 100 m2 x 0.012m = 1.2 m3

(This is wet volume of cement mortar (after mixing water) but we need dry volume. To get dry volume consider 35% bulking of sand and 20% wastages

= 1.2 m3 x (1+0.2+0.35) (Rather than 35% sand bulkage and 20% wastage you can add 1.54 as constant)
= 1.86 m3

Cement : Sand = 1 : 6

Sum of ratio =( 1 + 6) = 7

∴ Cement required

= 1.86 x 1/7 = 0.265 m3

= 0.265/0.0347 ( 0.0347 m3 = 1 bag  = 50 kg cement)

= 7.66 bags (≈ 8 Bags)

∴ Sand required
= 1.86 x 6/7 = 1.59 m3

Here we have calculated in Sq.m but you can also calculate it in Sq.ft.