Over time, buildings may require repairs to their plaster walls due to common issues such as crumbling, water damage, cracking, or separation from the lath behind it. These problems can arise as the building ages and can compromise the structural integrity of the walls if left unaddressed. As such, it is important to take steps to repair any damage that may occur to the plaster walls.
To address these issues, a process for repairing plaster walls can be followed. This process typically involves identifying the specific problem with the plaster, such as whether it is crumbling or cracking, and then taking steps to remedy the issue. This may involve removing any loose or damaged plaster, applying a bonding agent to the surface, and then applying a new layer of plaster to restore the wall’s structural integrity.
Repairing plaster walls can be a complex and time-consuming process, but it is essential to maintaining the safety and stability of a building. By following the appropriate steps and seeking professional assistance as needed, it is possible to address issues with plaster walls and ensure that they remain in good condition for years to come.
Repairing of Plaster walls
Procedures involved in repair of plaster are:
1. Identify Plaster Wall Problem
Prior to commencing any repairing operation on plaster walls, it is important to specify the type of damage that needs to be addressed. By doing so, the most suitable repair technique and equipment can be employed, resulting in the best possible outcome.
Table 1 provides a detailed list of different types of plaster wall problems and their causes. It is important to refer to this table to accurately identify the specific issue that needs to be addressed.
In addition to the information provided in Table 1, Figs. 1-3 depict the number of plaster wall problems that require repair. By referring to these figures, one can gain a better understanding of the scale and severity of the damage and plan accordingly for the repair process.
Table 1 Common types of plaster wall problem and their causes
| Common types of plaster wall problem | Cause of the plaster wall problem |
| Cracks | Hairline cracks due to moisture evaporation, delaminating crack because plaster pulling away from the lath behind it, and Settlement Cracks because of building settlement. |
| Damage | activity inside the home like a collision due to moving a piece of furniture |
| Blistering | improper slaking of lime particles in the plaster |
| Flaking | poor bond |
| Discoloration | Water seepage |
Fig. 1: Delaminating cracks in plaster wall
Fig. 2: Hairline cracks in plaster wall
Fig. 3: settlement cracks
2. Setting up Scaffolding
To ensure the successful completion of repair work, it is necessary to erect scaffolding. This provides a stable and secure platform for workers to carry out their tasks. Scaffolding is particularly important for repairs that involve working at height, as it helps prevent falls and other accidents.
However, in some cases, a ladder can be used as an alternative to scaffolding. This may be appropriate if the work can be safely carried out from a ladder, and if the ladder is secured properly to prevent it from slipping or tipping over. It is important to note, however, that scaffolding is generally considered to be the safer option, as it provides a more stable and secure platform for workers to carry out their tasks.
Fig. 4: Setting up scaffolding or ladder
3. Protective Measure
In order to ensure the proper maintenance of a building, it is crucial to protect various parts of it from the potential damage that can be caused by splashed mortar. This includes doors, windows, floors, and articles of furniture, among other components. These are all important elements of a building, and they must be safeguarded against any inadvertent harm that can occur during construction or repair work.
If mortar is allowed to splash onto these parts, it can result in unsightly stains or even permanent damage that is difficult and expensive to repair. Therefore, it is essential to take the necessary precautions to avoid this problem. This might involve using protective coverings or other measures to shield these components from contact with wet mortar during construction or repair work.
By taking these precautions, it is possible to ensure that a building remains in good condition and retains its aesthetic appeal. Whether constructing a new building or repairing an existing one, it is always important to be mindful of the potential damage that can be caused by splashed mortar and to take steps to prevent it from occurring. With the proper care and attention, it is possible to maintain the integrity of a building and ensure that it lasts for many years to come.
4. Cutting of Old Plaster
When repairing damaged plaster, the first step is to remove the mortar of the patch from the areas where the existing plaster has cracked, crumbled or sounds hollow when gently tapped on the surface. Once the damaged plaster has been identified, the patch is cut out to a square or rectangular shape at the exact position where repairing is needed. Care should be taken to ensure that the edges of the cut plaster are made under cut, creating a neat joint that will allow the new plaster to properly adhere and blend in with the surrounding area. This will result in a smooth and seamless repair of the damaged plaster.
5. Preparation of Surface
When removing old plaster, the masonry joints that become exposed must be raked out to a minimum depth of 10 mm for brick work and 20 mm for stone work. This raking process should be carried out evenly using a raking tool, and any loose mortar should be dusted off. The surface must then be washed thoroughly with water and kept wet until the plastering process begins.
For concrete surfaces, after the plaster has been cut out, the old plaster must be scrubbed thoroughly with wire brushes. The surface should then be roughened by wire brushing to create a pockmarked effect, and any resulting dust and loose particles must be removed. Finally, the surface should be washed and cleaned and kept wet until the plastering process begins.
Fig. 5: Surface preparation
6. Application of Plaster
A specific mix of mortar, such as 1:4 or 1:6, is used in conjunction with high-quality plaster sand for plastering purposes. Once the plaster has been applied to the surface, the finishing of the plaster is then carried out to ensure it blends seamlessly with the surrounding old plaster.
Fig. 6: Application of plaster
7. Curing of Plaster
For plastering purposes, a particular type of mortar mix is utilized, which may be a 1:4 or 1:6 mixture. This mortar mix is combined with high-quality plaster sand to achieve the desired result. Once the plaster has been applied to the surface, the finishing process begins. The purpose of this step is to ensure that the newly applied plaster blends in flawlessly with the surrounding old plaster. Achieving a seamless blend is crucial to the overall appearance of the surface. The finishing process involves careful attention to detail and skillful technique to achieve the desired outcome.
8. Finishing of Plaster
Once the plaster has undergone complete curing and drying processes, the next step is to apply paint to its surface. The chosen paint color should match or complement the colors of the surrounding area, creating a seamless and cohesive appearance. Painting the plastered surface with the appropriate color helps it blend in seamlessly with its surroundings, enhancing the overall aesthetic appeal of the area. Properly painting the cured and dried plaster ensures a smooth and uniform finish that looks natural and visually appealing, creating a polished look for the surrounding space.