What is the difference among cement plaster, cement render and cement screed? Under what situations should each of the above be used?
The purpose of plastering, rendering and screeding is to create a smooth, flat surface to receive finishes like paint, wallpaper etc.
Plastering is the intermediately coating of building materials to be applied on the internal facade of concrete walls or blockwalls. Rendering is the intermediate coating for external walls only. Screeding is the coating laid on floors to receive finishes like tiles, carpet, and marble.
Hence, these terms differ basically from the locations at which they are applied. Due to different locations of application of plasterwork, the proportion of material component for plaster and render is different. For example:
(i) Cement plaster
Undercoat- cement:lime:sand (by volume) = 1:4:16
Finishing coat – cement:lime:sand = 1:12:30
(ii) Cement render
Undercoat- cement:lime:sand (by volume) = 1:2:6
Finishing coat – cement:lime:sand = 1:3:6
This question is taken from book named – A Self Learning Manual – Mastering Different Fields of Civil Engineering Works (VC-Q-A-Method) by Vincent T. H. CHU.