Plastering

Plastering, a mixture of cement concrete and sand with water, is a thin layer of mortar applied over the masonry surface.

Plastering provides a finished surface that is firm and smooth which enhances the plastered surface appearance. It is used to cover rough walls, uneven surfaces, to conceal porous materials and to provide a suitable surface for painting. Plastering increases durabiliy and strengthened the applied surfaces.

In spalling concretes, the surfaces are first treated prior to applying two coats of plastering on it. Spalling concrete is a common issue for older buildings. It is caused by carbonation, a natural deterioration process. This causes the steel bars in the concrete slab to corrode and expand, which then causes the concrete  to crack and bulge. 

Repair jobs on spalling concrete usually involves the use of plastering works. Spalling concrete are normally found on ceiling spalling or beam spalling.

How to plaster a damaged wall, spalled ceiling or spalled beam

• Remove any loose or damaged cement plaster.
• Clean and scrub the wall surfaces thoroughly, removing any grease and dust.
• Any exposed and rusty reinforcement bars to apply with one coat of red lead primer.
• Entire wall roughen to give a good bonding to hold plaster.
• Apply two coats of new plastering cement and level to surface.
• Wait for new plastering to dry and cure.
• Fine sand paper on the new surface to achieve a smooth surface.
• Paint with a sealer coat and two finishing paint coats