Norfolk County Hall specified Flexcrete products to waterproof 2,000m2 of concourse podium decking where the existing waterproofing system had failed, allowing water to percolate through to the despatch bays below and rooms housing the four back-up generators.

Following removal of the paving and the failed system, repairs were carried out to the deck using Fastfill, a rapid setting, single component structural mortar. Allowing foot traffic within just 45 minutes of application, it is ideal for the repair of areas which cannot be taken out of service for long periods and just 7.5mm of Fastfill provides the same level of waterproofing as 1000m of typical concrete.

Cemprotec Elastic, an elastomeric, cementitious modified coating with excellent cracking bridging properties, was then applied to provide a seamless waterproofing system over the deck. Able to be applied to damp substrates at temperatures as low as 5°C, its dense matrix offers complete protection from water ingress, even at 10 bar pressure (100m head of water), as well as very high diffusion resistance to carbon dioxide gas to provide long-term protection to concrete. On completion, the concourse was overlaid with paving of the client’s choice.

Flexcrete products were also used to reinstate general areas on soffits where carbonation and water ingress had caused corrosion of the reinforcement and spalling of the concrete, particularly in the basement rooms and canopy to the loading and dispatch area. Monomix, a polymer and microsilica enhanced cementitious repair mortar, was chosen because of its ease of use and ability to be applied to soffits in thicknesses up to 80mm in a single application.

Requiring no primer, surfaces only need to be saturated but free from standing water prior to application. To provide an aesthetic finish and maximum protection to the concrete from further degradation, Monolevel FC was used as a fairing coat to fill minor voids and defects and provide an even surface. Monodex Smooth, a high performance anti-carbonation coating, was then applied which provides the same degree of protection as 300mm of good quality concrete cover.

All products used are CE Marked in accordance with BS EN 1504 Products and Systems for the Protection and Repair of Concrete Structures, which was a specific requirement of the client.