When you mention building construction material one naturally thinks of gypsum powder among many other things. Gypsum powder is heated to remove the water molecule and carbon dioxide. It becomes calcium sulphate hemihydrate (CaSO4.½ H2O) which is called plaster of Paris. This calcium hemihydrate converts back to calcium sulphate dihydrate when you add water to it.
Uses of gypsum powder
Gypsum powder is used for finishing the walls and concrete blocks. You could also use it for ceilings and columns. Most of the builders get their gypsum for building work from the Gypsum Powder suppliers in their locality. Gypsum is calcium sulphate dihydrate (CaSO4.2H2O). The method of preparation of the gypsum is by mining the mineral, heat dried and then crushed to a fine powder. This powder finds diverse applicability such as for fertilizer, as blackboard chalk, and for making plaster board.
When used for building construction, the gypsum powder must adhere to specific conditions. It must have a bulk density of 1020kg/m2 and a 25 kg bag must provide coverage of 21square feet when the thickness of the plaster is 13 mm. The setting time must be 25-30 minutes and it must have a compressive strength of 60-70 kg/cm2. The colour of the finished surface must remain super white. You can contact the Gypsum Powder manufacturers and find out if their gypsum powder matches these specifications.
Use for plastering surfaces
Gypsum is light and has high fire resistance and when used to finish the surface of walls and other concrete surface provides a level and smooth surface. You can apply this directly and once finished it does not need any curing. It provides an inert surface to paints and chemicals. It dries quickly and you can paint it within 3 days of finishing application.
It does not show tension or shrinkage cracks and is long lasting. Users will have walls that are blemish-free even after 20 years. It shows remarkably low thermal conductivity so it can be used in the outer walls to keep the heat out. This is the reason people are choosing gypsum over cement plaster for their walls.
It takes paint readily. Considering all the advantages of gypsum plaster, builders use it for their constructions and reap the benefit.