WHAT ARE THE RECOMMENDED PLASTER SPECIFICATIONS FOR DIFFERENT SITUATIONS?

Recommended Plaster Specifications

A list of specifications for blends suitable for various conditions, including single-coat, two-coat and three-coat work, is given in the table below.

number of plaster coats

Situation

mix by volume

(cement:lime:sand)

single coat plaster both internal and external 1:0:3
1:0:4
1:0:6
1:1:6
1:2:9
two coat plaster both internal and external
(a) under coat 1:0:3
1:0:4
1:0:6
1:1:6
(b) finishing coat 1:0:3 to 6
1:1:6
1:2:9
three coat plaster very rough surface; both internal and external
(a) base coat 1:0:3
1:0:4
1:0:6
1:1:6
(b) second coat 1:0:3 to 6
1:1:6
1:2:9
(c) Finishing Coat Coarse lime and fine sand or marble dust in equal proportion

notes to remember

  • Where two or three coats of plaster are adopted, as far as possible the undercoat mixture should be coarse sand (corresponding to grading zone 2), with a fineness modulus not less than 2.0.
  • The fineness modulus of sand for single coat plaster should be as high as 1.5. The strength of the plaster mix decreases with a decrease in the fineness modulus of sand.


Er. Mukesh Kumar

Photo of author
Er. Mukesh Kumar is Editor in Chief and Co-Funder at ProCivilEngineer.com Civil Engineering Website. Mukesh Kumar is a Bachelor in Civil Engineering From MIT. He has work experience in Highway Construction, Bridge Construction, Railway Steel Girder work, Under box culvert construction, Retaining wall construction. He was a lecturer in a Engineering college for more than 6 years.