Sika supplied the corrosion-resistant repair solution as part of a huge refurbishment involving six social housing tower blocks.
The Brentford Towers in west London form an imposing cluster in an estate within the capital’s Hounslow district. Built between 1968 and 1978, the towers contain 88 homes in each of 6 twenty four storey point blocks with exciting views over the Thames and West London. Over time, the structures’ concrete façade had become cracked and spalled in areas, leading to Hounslow Council implementing a repairs programme as part of a major overhaul of the buildings.
UK Gunite was selected to apply the Sika repair system on behalf of the project’s main contractor, Engie UK. With work starting in 2017, it initially involved applying Sika® FerroGard®-903+, a surface-applied mixed corrosion inhibitor. This ingenious solution, which is based on organic compounds, is designed for use as an impregnation of steel- reinforced concrete. It is spray-applied and penetrates concrete to form a protective monomolecular layer on the surface of the reinforcing steel, thus delaying the corrosive process and the rate it progresses.
Surface cracks and spalling were then repaired using Sikagard®-545 W Elastofill. This quality product provides a crack-bridging intermediate coat, which closes pores, cavities and blowholes. It also offers excellent resistance to water ingress and damp. Sikagard®-550 W Elastic provided the concrete surface’s crack-bridging protective coating. Class ‘O’ fire-rated, Sikagard®-550 W Elastic the product is particularly ideal for exposed concrete structures susceptible to cracks and openings and the like. For the Brentford Towers refurbishment, Sika’s repair and corrosion protection solution was used across a surface area covering 25,000m².
John Dorling at Engie, said: “This was a huge project to undertake. Therefore, we required a concrete repair and protection system that was proven to be effective over large areas. The spray-applied Sika® FerroGard®-903+ was not only the best solution in terms of the protection it offered, it was also the most time and cost-effective, as its penetrative properties negated the need to break-out large areas of concrete. The Sikagard®-545 W Elastofill was also a revelation in terms of its crack-bridging ability and the light-grey finish it provided.”
Cllr Lily Bath, Cabinet Member for Housing and Social Inclusion, Hounslow Council, said “We are excited to be working with Sika, Engie and other suppliers to repair and return these iconic buildings to the landmark status that they have in West London, and to a condition that our residents deserve.”
By specifying Sika’s concrete repair and corrosion protection system, the project’s clients, Hounslow Council, have a 15-year guarantee on work involving large areas of concrete with carbonation beyond the depth of the reinforcement. Therefore, the structural integrity of these striking tower blocks has been future-proofed for the reassurance of client and occupants.