Cement plastering can be used to coat both the external and inner walls. Cement plaster can be applied in one coat or two coats.
How to Plaster a Brick Wall : Step-By-Step
Step-1-Preparation for plastering
Double-coat plaster is used when the plaster thickness is greater than 15mm or when it is necessary to achieve a very fine finish.
There are four steps to apply a double coat of cement plaster to a wall surface.
Step-2-Groundwork for plaster
Step 3 – Applying the first coat (or undercoat or rendering coat)
Step 4 – Applying second coat (or finishing coat)
FIRST STEP- (PREPARATION SURFACE FOR PLASTERING).:-
- To give plaster a strong bonding, keep all mortar joints rough.
- Use a wire brush to clean all joints and surfaces. Do not leave oil or grease on the wall surfaces.
- To bond the plaster better, rake the mortar joint out to at least 12mm if the surface is not smooth.
- If your wall projection is greater than 12 mm, you can remove it and create a uniform wall surface. This will decrease the amount of plaster required.
- Fill any holes or cavities in the surface with the appropriate material.
- To plaster the wall, roughen it.
- Before plastering, wash the mortar joints and wall. Keep it moist for at minimum 6 hours.
SECOND STEP (GROUND WORK FOR PLASTER).:-
- To ensure uniform plastering thickness throughout the wall’s surface, you must first place dots onto the wall. A dot is a patch of plaster measuring 15 mm x 15 mm in size and with a thickness of approximately 10 mm.
- The dots are placed on the wall at approximately 2 meters, covering the entire wall surface.
- Using a plumb-bob, check the verticality of the dots one after the other.
- The vertical plaster strips, also known as screeds are created between the dots by fixing the dots. These screeds are used as gauges to ensure that plaster is applied at the same thickness.
THIRD STEP- (APPLYING FIRST COAT, UNDER COAT, RENDERING COAT)
- Brick masonry has a thickness of 12 mm for the first coat plaster, while concrete masonry can vary from 9 to 15.
- For first coat plaster, the ratio of cement to sand varies between 1:3 and 1:6.
- Place the plaster first coat between the spaces created by screeds on your wall surface. This can be done with a trowel.
- Use flat wooden floats or wooden straight edges to level the surface.
- After leveling the plaster, allow it to dry before applying the second coat.
FOURTH STEP- (APPLYING THIRD COAT, FINISHING COAT, OR FINE COAT:-
- The thickness of the second or final coat can vary from 2 to 3 millimeters.
- For second coat plaster, the ratio of cement to sand varies between 1:4 and 1:6.
- Be sure to evenly dampen the first coat before applying the second coat.
- Finish coat the surface with wooden floats. Use a steel trowel to finish it off.
- To eliminate any joining marks, the final coat should be applied from top to bottom. Note: After plastering in auckland is complete, you should keep it wet with water for at most 7 days to build strength and hardness.