By mixing cement and sand in the right proportions, a plasterer can give your home's walls and ceilings the final touches needed to create a smooth finish, just before your paint your home. However, down the line, your plastered house may once again need re-plastering. This may be caused by varying reasons. Read on to see what they are and how to identify them.

Cracked plaster

One sure sign that your plaster is in need of a re-do is cracking. Cracking of plaster can be caused by a number of reasons. These include: not applying enough water into the plaster mix so that it dries out later, applying very thick layers of plaster or not mixing the sand and cement proportions as required. Plaster cracking can vary from mild (where the cracks are not visible from far) to severe (also called gator cracking). If mild, the plaster can be coated over. However, if severe, the old plaster will need to be stripped and redone.

Peeling/spalling plaster

Peeling plaster, or spalling plaster, is where the plaster coat starts to come off the walls or ceiling surface, leaving bare patches behind. This is often caused by the plaster not adhering well to the original surface. This can be brought about by several reasons: The wall was dirty or dusty; the wall was too dry or too wet; or the mixture used in the plaster was not correct. When it comes to the latter cause, use of too little cement in the mixing ratios could be one of the potential reasons. In some cases, spalling plaster can be caused by concrete cancer, i.e. where the rebar in the walls has rusted and is expanding, pushing the plaster out. In either cases, a complete re-plastering of the affected areas will be required.

Water penetration

Water is a major cause of damaged plaster in walls and ceilings. Water penetration in a home can be caused by leaking external plumbing or rainwater. Water penetration on plaster can be detected through water stains, mould or rust-coloured water stains due to the rusted rebar. Sometimes, moisture creates a powdery residue on the plaster surface as well. Often, moisture damage on plaster is caused by lack of proper waterproofing during construction. This can be amended by installing waterproof membranes or re-plastering using a waterproof mix.

If you detect any of the above in your house's internal walls, external walls or ceiling, get it fixed as soon as possible before the damage spreads. Contact a domestic plasterer like JDP Interior Linings for an inspection and cost estimate.