You may be considering painting or wall-papering the concrete walls, or ceiling slab, of your home or office. Before embarking on the task, you should inspect carefully to make sure that there are no cracks or patches that have appeared in the concrete. These may be signs of concrete cancer and cannot be simply painted over or covered.
What is concrete cancer?
Concrete cancer is the name commonly given to any patches of deterioration in structures made out of concrete, including walls and concrete floor or ceiling slabs. The damage may vary from cracks to eroded patches of differing sizes in the concrete. The deterioration usually occurs over time.
What causes concrete cancer?
Weathering and poor workmanship
Weather can have a destructive influence on concrete, as can the particular atmosphere in which a building stands. Concrete will react to both warm, humid climates, as well as cool, dry climates, possibly resulting in cracks or patches in the structures.
Poor workmanship can also contribute to the deterioration of concrete, as can the use of a bad grade of concrete in the first place.
Rusting of internal steel bars
When a wall or floor slab is made out of concrete, there is an internal network of steel bars that create the frame of the structure. The concrete is filled in around these bars and the structure is given the desired shape. If any of these steel bars starts to rust, the integrity of the wall / slab will be compromised and deterioration may occur. This disturbs the concrete around the bars and it begins to crumble. The rust can also alter the chemical balance in the concrete, which may also lead to crumbling and cracks developing in the structure. It is then easy for water to penetrate the concrete and this causes further deterioration, which may contribute to the rusting of the reinforcing bars.
Damage caused to the steel reinforcing bars by water or wear and tear is the main cause of concrete cancer.
How is concrete cancer treated?
The only way to treat concrete cancer is to remove the cause of the deterioration. This usually means cutting into the solid concrete to expose the steel bars. These will have to be treated for rust to prevent further weathering from occurring. If the bars are severely damaged, sections may have to be removed and replaced. Once the bars have been treated, the area around them can be filled in with fresh concrete and the structure can be made whole again.
If you detect signs of concrete cancer in the concrete walls or ceiling of your home or office building, you must have them checked and repaired before considering painting or hanging wall paper.