What is Plaster of Paris ?

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Plaster of Paris is basically a building material that consists of a fine, white-colored powder, known as calcium sulfate hemihydrate. The Egyptians, Greeks and Romans used Plaster of Paris for sculpting their tombs and other monuments, as well as for fireproofing in buildings. Plaster of Paris is obtained by heating gypsum or calcium sulfate dihydrate to about 140 - 180°C. When gypsum is heated to such a temperature, it loses three-quarters of its water content, leading to the formation of Plaster of Paris. The name Plaster of Paris is derived from the large deposits of gypsum in the Montmartre hill in Paris.


USP of Shriram Nirman P.O.P.

  • Shriram Nirman P.O.P. is one of the best quality P.O.P. available in the market today, with very low silica content, which gives saving over other P.O.P.s.
  • It gives high strength on setting with extra white colour The ultra white P.O.P. gives whiter surface and reduces the consumption of paint.
  • Superior fineness gives good workability and more area coverage. It also gives strong bonding with wall and ceiling.
  • Perfect setting time (Initial: 15 to 20 minutes Final: 28 to 30 minutes) This reduces wastage during application, and provides a crack free surface.
  • Consistent quality and weight-Each lot of Shriram Nirman P.O.P. is subjected to stringent quality control and checks to ensure the best quality is delivered to the market. Each bag delivers the quantity as promised lot after lot.
  • It is the ultimate choice of customers for beautifying the interiors and providing aesthetic appeal to their dream homes

Below are the 3 main criteria’s of a good P.O.P.:-


  • Highlevel of CaO & SO3 gives good whiteness
  • High purity of gypsum leads to whiter finish products

Level of residue(Reta)

  • Residue is insoluble particles in P.O.P.
  • Minimum 2.5% residue is required for strength.
  • More residue leads to blackness of material and problem in finishing

Setting time

  • Setting time is achieved due to proper heating of gypsum in calcination process.
  • Late setting time leads to less wastage of P.O.P. as contractor have more time to apply the material.
  • Fast setting time leads to more wastage of material.
  • Proper setting time for making paste for application is about 5 to 8 minutes (Ghol Tyyar Hona), initial setting time is around 15 to 20 minutes and ideal final setting time is 28 to 30 minutes


  • Fineness is achieved by grinding of calcined gypsum
  • Fineness gives more coverage hence cost of application is reduced.