Sika Concrete Repair and Protection

When an external concrete staircase at the headquarters of a UK government department, in Central London, started to show significant areas of concrete spalling, a fast and reliable repair system was required. For this, specialist contractor Cemplas specified the Monotop Repair System from Sika, global leading manufacturer of construction products.

When the government building’s in-situ staircase began to exhibit some severe structural deterioration – including spalling concrete falling away and advanced steel corrosion – a fast solution was of utmost importance to meet health and safety standards.

Bradbrook Consulting Engineers was commissioned to provide a condition report and specification. Following a successful tender, and having successfully worked together on a number of previous projects, the company appointed waterproofing and concrete repair specialists, Cemplas, to complete the repairs.

Following the identification of the affected areas, Cemplas undertook a series of hand-applied repairs, using Sika Monotop 615 followed by an overall levelling coat of Sika Monotop 620. A cementitious two-component system, Sika Monotop comprises polymer modified mortars, to repair the damaged substrate. The system also contains silica fume, a highly reactive pozzolan, which is applied “wet-on-wet” to ensure no degradation of the concrete or the structural steel. With its excellent resistance to water and chloride penetration, whilst repairing the concrete it also helps to prevent future damage to the stairwell’s substrate.

After remedial repairs were completed, two coats of Sikagard 550W Elastic, the anti-carbonation protective treatment system, were applied. Offering excellent crack-bridging properties and long term performance, as well as meeting the requirements of BS EN 1504, the treatment ensures the newly refurbished concrete is protected from water, carbonation and chloride intrusion.

Completed on time and on budget, Cemplas and Sika ensured that the stairwell at the government building easily meets stringent health and safety requirements. Thanks to the 10 year workmanship certificate issued by Cemplas on completion of the project, complementing the long term performance of the Monotop Repair System, the staircase will continue to offer outstanding performance and protection for many years to come.

For further information on Sika’s range of products visit http://www.sikaconstruction.co.uk or for general enquiries including technical, on or off site support, please call 0800 1123863.