Concrete Repair Solution for Iconic, High-Rise Trellick Tower
This spectacular concrete edifice stands today as a fine monument to Modernism’s revival having escaped a terrifying reputation during years of poor security and badly managed community living. Now a sought-after location with surprisingly spacious accommodation, Trellick Tower is structurally sound and receiving well-deserved TLC.
The BBA-approved weber.cem concrete repair system is now securing the exterior concrete surfaces where localised water ingress has rusted the re-enforcing steels causing small patches to “blow” giving surface damage to the high-density pebble finish. The damage is cut out, steels treated or replaced and a new surface concrete applied to exactly match the colour and texture of the existing facade.
English Heritage is responsible for approving any exterior treatment to this Grade 2 listed property and extensive sample trials were carried out to achieve the best colour and texture match for the weber.cem repair material. Initially the pebbles were effectively “dashed” onto the repair cement but this did not achieve the correct level of bond and resulted in greater amounts of pebble surface area showing than the original surfaces.
Ultimately David Wylie of Weber and Greg Stefanic from approved contractor Concrete Restoration created the correct process of mixing the right quantity of pebbles with the weber.cem HB30 repair concrete which then, 24 hours after installation, receives a light surface wash to bring the correct amount of pebble surface into view. “Weber always claims to have an answer to any concrete problem and this was a good example of creating a version of our system that meets all requirements,” said David Wylie.
The Trellick Tower renovation project includes replacement windows and other repairs and the main contractor is renovation specialist, Breyer Group. Dan Kerney is the QS and Ges Tibbenham, the Contract Manager for the project. “Overall there is nearly 10,000m2 of wall surface to be surveyed to locate problems prior to any remedial work being undertaken,” says Mr Kerney.
The weber.cem system is being applied by Concrete Restoration Limited who has worked in this specialist field for forty years. The Company is ISO accredited with 50 in-house, fully trained staff and Paul Griffiths explains the enormity of the project. “We require 31 storeys of full scaffolding to facilitate the final repair area survey which identifies and numbers each individual repair locations. The surface is then power washed and the damaged material chipped out in a straight edge zone to reveal the reinforcing bars. We remove the concrete from below the rebars to get maximum purchase for the new infill. If required we cut out the old bars and drill into the remaining concrete to fit new bars that are wired to sound steel before being primed with weber.cem keycoat which is a single component, polymer modified corrosion inhibiting bonding primer for parent concrete and steel reinforcement.” “
The weber.cem HB30 and pebble mix is then applied. HB30 is a high-build, polymer modified repair mortar that is compacted by hand and finished with a wooden float. We return to the area after 24 hours to wash the surface to bring the pebble display up to match the original surface texture and stone density. This is a massive project for us but it is really quite a privilege to be working on this iconic building, especially as it is Grade 2 listed,” says Paul Griffiths.
