Concrete slabs and walls can form small cracks over time. This can be due to shrinking, poor workmanship or constant wetting and drying. Even though these cracks do not initially affect the structural integrity of concrete element, it can cause water leaks. This will lead to concrete cancer and spalling, which will compromise the structural capacity of the concrete elements.
Together with our engineering partners we are able to identify the underlying causes of the leaks and provide the appropriate rectification methods to push moisture out of existing concrete elements and provide a seal preventing the leaks from causing further damage to the structure.
Some structures requiring leak sealing:
Concrete roof tops or suspended slabs exposed to water/rainfall
Utilities and below ground assets including concrete sewer/drain pipes and pits
Liquid storage tanks
Basement retaining walls
Tunnels
A suspended slab with a roof top terrace and garden bed: If minor cracks occur, and the water in the rain garden leaks into the apartment below there are two options.
Conventional Repair: Remove all trees, vegetation and soil, and strip all waterproofing. Once all stripped, the area is to be cleaned, dried and waterproofing reapplied. Only once this is done, can the garden bed be reinstated, and terrace re-opened for public access. This requires permanent closure of affected area, it is also time consuming and expensive.
Our solution: Inject polyurethane resin into the crack through the slab from below; until the crack is fully sealed and the water leak has stopped, providing a permanent waterproof seal. This is not only non-invasive, it will only take a fraction of option 1.
A basement wall on a site boundary has a leak through it. There are 3 options:
Conventional Earthworks: Expose the wall from the leaking side, this will require access to the neighboring property and the use of heavy machinery to expose the wall and re-apply waterproofing. This will require permits and permission from your neighbor, will be very costly and may take weeks.
Hide the Leak: Create a false wall, or provide a seal on basement wall so no leaks are visible. However, since water is still entering the crack, this will lead to concrete cancer and further degradation and no ability to monitor the failure.
Our solution: High pressure inject polyurethane resin into the crack, not only sealing the crack but also providing a negative side waterproof seal.