Calculation of Cement and Sand for Plastering Excel Sheet
Thickness of Plastering
Finishing coats (and single-coat work, where employed)shall be of such minimum thickness as just to provide a sufficient body of material to harden satisfactorily under the site conditions in any particular case.
The total thickness of two-coat work exclusive of keys or dubbing- out shall be generally about,but shall not normally exceed 20 mm and it shall not exceed 15 mm in the case of in situ concrete soffits.
The thickness of three-coat work shall be about,but shall not normally exceed 25mm.The thickness of an individual coat shall generally be as recommended
The mix for the finishing coat shall depend on the texture and colour of the surface desired. If the surface is to have a lime-putty finish,then it is advisable to have rich mix of 1 part of cement,1 part of lime and 3 parts of sand.For any rough finish a mix of 1 part of cement to 3 to 4 parts of sand is recommended.
PREPARATION OF PLASTER
The material used in the preparation of plastering mixes may be measured by volume using gauge boxes.Cement shall be measured by weight. For the purpose of proportioning one cubic metre of cement shall be taken to weigh 1440 kg approximately. Proportioning of lime may be done by measurement of volume as lime putty or dry hydrated lime before the preparation of putty.The mix proportion of lime, unless otherwise stated,generally refers to the volume of putty.
Quantity of Water: For general cement-plaster work with 1 : 3 proportion the quantity of water required is about 70 percent by weight of cement.
A) The nature and condition of the fine aggregate;
b) The temperature and humidity at the time of working;
c) Richness of the mix, namely, whether rich or leaner than 1 : 3;
d) The varying quantities of lime in composite mortars; and
e) The use of admixtures added for improving the workability.