While the current economic climate is placing downward pressure on property prices, there is one thing that owners can do to enhance the value of their property – repair it.
It is essential to provide adequate surface protection in the form of high quality decorative or specialist coatings and waterproofing products in some cases.
Wear and tear resulting from South Africa’s weather extremes will reduce the value of a property over time and is unfortunately unavoidable.
Unsightly damage and decay, if left untreated or cheaply repaired, can potentially lead to the deterioration of building fabric, such as spalling, and eventually lead to expensive repairs.
Spalling is the rupturing of sections of concrete from a structure. These sections appear to be “popped” and can vary in size from a few centimetres up to metres long.
There are several factors that can cause concrete to spall, but the three main culprits are chloride ingress, carbonation and chemical attack.
These corrode the reinforcements which then expand, causing the surrounding concrete to crack away from the structure.
Richard Williams, CEO of the Gordon Verhoef and Krause Group of Companies, says spalling can cause injury to people and damage to property as chunks of concrete tend to fall off the building.
He says these can lead to pricey liability claims against building owners. What’s more, the cost of returning the property to a sound state increases if the spalling is not promptly addressed.
Step 1 – get a diagnosis
He advises property owners to enlist the services of a specialist contractor with experience in dealing with spalled concrete to inspect and diagnose their property.
“Spalling is usually readily visible to the trained eye, however, there are cases when the extent cannot be easily assessed from a visual survey.”
In such cases, it is advisable to conduct a comprehensive survey to determine the extent and severity of the problem, the appropriate repair procedure and a realistic budget for repairs he added.
Step 2 – repairs
Gordon Verhoef & Krause, with its vast expertise in handling spalled and cracked concrete as well as delaminating or failed plaster, has recently conducted repairs to the sea-facing facades of an apartment block in Umhlanga, after diagnosis revealed extensive spalling concrete.
A typical repair procedure consists of marking all areas of spalled concrete and breaking out all of the loose and defective material to expose the corroded reinforcing.
Sufficient concrete must be removed to enable access behind the reinforcing and to expose the full length of corroded rod. Tests should then be conducted to identify any remaining carbonated concrete which may appear to be sound.
Step 3 – clean corroded reinforcing
The next step is to clean the corroded reinforcing by mechanical means or grit blasting. In some cases it may be necessary to replace steel entirely.
Step 4 – apply protection
Once this is complete, protective coatings and a bonding primer that have been manufactured specifically for spalling repairs are swiftly applied to the reinforcing and repair area.
Depending on the specifics of the site and the nature of the spalling, other products such as migrating corrosion inhibitors may be used to limit the risk of future spalling.
All too often we see spalling repaired by the process of knocking off loose concrete and patching with cement mortar. While this may seem cheaper, such a repair is guaranteed to fail within a very short period, explains Williams.
Step 5 – added protection
The final stage entails the application of the specialist repair mortar in layers, ensuring that each layer is properly compacted before the next is applied.
On completion of the repairs, it is essential to provide adequate surface protection in the form of high quality decorative or specialist coatings and waterproofing products in some cases. These will protect the structure and minimise the risk of future deterioration.
An on-going maintenance programme and budget should also be planned with the assistance of the contractor.
William says by making use of experienced specialist contractors the cost of these repairs are ultimately more economical than a short-term, cheap repair and can enhance the value of the property.
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