Total Corrosion Management system supplied for Four Squares renovation

Sika has supplied a ‘total corrosion management’ solution to the £12.9 million regeneration of a residential estate in Bermondsey, South London.

Built in the early 1970’s, the Four Squares Estate is made up of 691 homes across four near-identical seven-story blocks – New Place Square, Lockwood Square, Marden Square and Layard Square.

After a structural inspection carried out by consulting engineers Arup, the Four Squares estate was deemed structurally sound, however large areas of previously uncoated concrete were exhibiting reinforcement corrosion, in addition to stalactites, excessive sediment, and efflorescence caused by leaking balconies.

Sika Ferrogard 903+

Over the past four years, Southwark Council has invested £326 million into ensuring every one of its homes is warm, dry and safe by 2016.

Working in collaboration with clients Keepmoat and Southwark Council, specialist contractor Barwin and Sika carried out on-site trials using Sika Ferrogard 903+ corrosion inhibitor across all the external elements.

The trials demonstrated its ability to successfully penetrate the concrete, reach the steel and restore it to a state of passivity.

Sika Ferrogard 903+ was included in Sika’s total corrosion management specification which also included repair mortars and protective coatings.

Ferrogard 903+ is designed to extend the service life of aesthetically valuable concrete surfaces. Over 60,000m2 of the product was spray-applied by Barwin, penetrating the concrete to provide a protective layer around the steel reinforcement whilst maintaining the aesthetics of the structure.

Total Corrosion Management

Following the application of Ferrogard, Barwin applied the two part Sika MonoTop to make repairs to the damaged concrete frame.

Sika’s corrosion management solutions are suitable for a wide range of concrete repair applications; from bridges and housing to car parks and commercial buildings.

The first layer of Sika MonoTop is designed to inhibit corrosion and improve the lifespan of steel reinforcement. It also acts as a bonding bridge for the second layer – a repair and re-profiling mortar.

SikaGard was applied as a final layer of weather protection. A SikaGard – 675W anti-carbonation coating was applied to soffits and remaining concrete surfaces, except ringbeams, to seal against the ingress of water, chlorides and carbonation. 

In addition, SikaGard – 550W Elastocolor was applied on horizontal surfaces and ringbeams to prevent the ingress of carbon dioxide and moisture whilst permitting two-way water vapour diffusion. 

Thanks to the comprehensive corrosion management system, Sika helped to restore the Four Squares Estate to make them warm, dry and safe for years to come.

Sika Limited
Watchmead
Welwyn Garden City
Hertfordshire
AL7 1BQ
Telephone: +44 (0) 1707 394444

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