Fosroc International Limited

The new Ardley EfW Plant, including a 12m basement built over an Artesian Well, presented a host of construction challenges. Due to the extreme water pressure created by the Artesian Well, as well as ammonium salts in the ground, Fosroc worked closely with Tata Projects specifying a solution using Proofex Engage to provide a watertight, chemically resistant barrier, with Supercast SW20 in the construction joints to reinforce the floor to wall joint. Fosroc provided a ‘total solution’ package to ensure Tata Projects could feel confident with the proposed specification, from basement waterproofing, to grouting crane bases, flooring and sealants.

Bridport House using Cemtop GP.

THE PROJECTCanterbury Riverside is a major new residential development designed by PRC Architecture for Bouygues Development\Link City. Its construction has been in progress since 2020, and in January 2022, the main contractor for one of the housing elements, Jenner Ltd, commenced work on the below-ground Block 11-13 car park. Jenner appointed specialist contractor GSE to install a new ground bearing slab within the car park, which would tie in with existing columns and retaining walls. The dimensions of the slab required movement joints to be accommodated and there were multiple access points that required waterproofing detailing. The design and installation was also required to meet the requirements of the NHBC (National House Building Council), so Fosroc was appointed to supply materials, and Waterproofing Design Services to carry out the design work. Jenner had previously worked with both Fosroc and WDS on block 14 of the project to provide gas resistant membranes and design.THE SOLUTIONSupercast Crystalline Waterproof concrete was selected due to its robust waterproofing response to any potential ingress through the ground bearing slab. Supercast PVC waterbars were also installed at every movement joint, with the complete Fosroc joint solution installed via Hydrocell XL closed cell compressible joint filler and Nitoseal MS300 joint sealant, which protected the joints against damage from traffic. Care was taken to design a fully linked waterproofing system around the joints between the new slab and existing column bases. This element was closely coordinated with the installing contractor (GSE).THE BENEFITSPour sizes and schedules were optimised by careful design and coordination. A flexible and fully watertight solution was achieved, and regular dialogue with the installing contractor ensured obstacles were swiftly overcome. Feedback from GSE was positive, with Site Manager Darren Knight commenting “This was the first time we had installed the FOSROC products on a waterproof detail. The advice and the back up from the team was very good and Paul Hitchins was on hand all along the install route to aide any issues, promptly answering our questions. The products were easy to install, and regular on-site inspections ensured a smooth install throughout. I would have no issue installing this product on any other job when specified.”

THE PROJECTThe village of Comrie is located towards the western edge of the Perth & Kinross Council area, approximately 40 kilometres west of Perth in Scotland. The waterproofing system used to cover the buried water tank at Comrie Distribution Service Reservoir (DSR) was many years old and had failed. As part of the ongoing Scottish Water SR21 framework, Fosroc and The Fraser Bruce Group have developed a wide range of solutions for waterproofing water tanks that have been proposed and agreed by both Morrison Construction and Scottish Water. This project involved removing the soil overburden and the existing waterproofing system, before mechanically preparing the deck and applying sheet membrane.THE SOLUTIONOnce the overburden and existing waterproofing were removed it was apparent that there was severe ponding on the tank roof. The decision was taken to prepare the deck and apply an external self-leveler to prevent the ponding of water. The perimeter and upstand detailing was carried out before Fosroc’s self-adhesive sheet membrane Proofex 3000 was applied to the primed, horizontal surface. The surface was then protected with Proofex Sheetdrain 80, a drainage and protection membrane. After the membrane was laid, the access hatch upstands received two coats of Nitocote CM210 before more Proofex 3000 was applied and terminated just below the height of the new overburden. The access hatches were then sealed in place with Nitoseal MS600.THE BENEFITSProofex 3000 membrane, which is cold applied and comes in 1m x 20m rolls, is self-adhesive, thereby reducing the amount of product and application time. The applicator was able to cover large areas in far less time. The membrane is made from cross laminated HDPE film to protect against damage, while still being sufficiently flexible for detailing around corners. It is resistant to ground water, soluble sulfates and chlorides, offering robust protection from aggressive ground salts. Its use with Sheetdrain achieved a high quality, reliable installation compliant with EN 13707:2004. By combining the use of Nitocote CM210 and Proofex 3000, Fosroc were able to provide solutions for both exposed and buried areas of the tank with no compatibility issues between the products.

County Donegal Watewater Treatment Plant concrete repair and Industrial flooring.

Fosroc contacted the designers of the Victoria Dock project in early 2013. Working with the design team Fosroc UK used its highly experienced sales and technical staff to produce a waterproofing solution using Supercast PVC waterstop and Supercast SW hydrophilic waterbar. Materials including special angles were hand made at our Tamworth manufacturing plant and passed the scrutiny of the Crossrail approvals team. To ensure watertight construction Fosroc provided on-site training on product installation. Materials used on C340 have since been passed for use on other rail projects.

Crown House is a change of use project from an old 1960s office block into modern student accommodation and highlights the opportunity to repair and refurbish concrete structures to provide much needed housing for local communities. The refurbishment and repair approach is of course, significantly greener than a complete demolition and rebuild, particularly in a busy town location such as Brighton. The concrete surveys found issues with the underlining substrate, including carbonation, so the project required a specification which would ensure protection of the concrete, in addition to a pleasing aesthetic finish for the client and student residents of the new block.

THE PROJECTFulwith Mill in Harrogate is located in an exclusive upmarket area – so much in fact, in 2019 Fulwith Mill Lane was named by Zoopla as the most expensive road in Yorkshire. For this new build project, Fosroc were asked to specify suitable products for the waterproofing aspect of the basement construction. The main challenges included a high water table, high clay concentration in surrounding area leading to a perched water table, and potential for hydrostatic pressure against the basement construction. Howard Civil Engineering was the main contractor for the project, with Fosroc being selected as materials supplier due to a long standing relationship between the companies, and a number of previous deployments.THE SOLUTIONFully bonded Proofex Engage membrane was used on the basement slab, combined with Supercast Watertight Concrete Powder (WCP) to provide a high level of resilience to both water ingress and potential defects. Supercast WCP is a concrete admixture that reduces porosity and permeability, increasing water and corrosion resistance. The vertical elements were cast in Supercast WCP with Proofex 3000, to provide a greater degree of flexibility to enable the contractor to install effectively in the tight spaces around the site, and around the complex shape of the structure. Proofex 3000 is a cold applied, highly flexible waterproof membrane – ideal for application of membrane around intricate building features.THE BENEFITSThe products specified for this project provided multi-layered and seamless protection to the underground element of this exclusive residence to meet stringent BS8102 Type A waterproofing standards. Proofex Engage provides water, water-vapour and gas protection to water excluding structures such as basements, and protects concrete from aggressive ground salts, chemicals and hydrocarbons. It is supplied with a self-adhesive strip on one side of the roll to provide sealed laps and comes with a range of auxillary products (for this project, Supercast SW20 Hydrophillic Waterstop) to form a complete waterproofing solution and simplify application for the contractor. Its unique mesh system bonds permanently to concrete, remaining in pace even if settlement takes place – the exceptionally high bond strength of Proofex Engage - 2.96kN, sets it apart from the competition, at 70% stronger than the leading chemically bonded membrane.

The innovative new low odour, non-taint polyaspartic based floor coating, Nitoflor PAFS, was used to rejuvenate the floor of a poultry processing area.

Gowriehill Distribution Service Reservoir is located in Dundee City and managed by Scottish Water. In late 2021, part of the reservoir tank construction was discovered to have a brittle asphalt waterproofing layer over the top of a beam and block roof. Fosroc proposed a solution that was easy to apply and provided a robust watertight finish and a 20 year warranty.

THE PROJECTThe M3 Hackwood Road Bridge is located near Basingstoke on the M3 motorway. It required extensive concrete repair over large areas, due to water ingress causing the corrosion of the steel reinforcement through carbonation and chloride attack. The repairs were undertaken as part of the Scheme Delivery Framework (SDF) for National Highways. Continuity and half-cell tests carried out revealed weak areas within the bridge’s rebar.THE SOLUTIONSacrificial anodes were installed to the perimeter of all repair areas prior to Renderoc DS being used to spray back replacement material. Renderoc was selected as the best product solution due to its low rebound performance, which is well-known and tested in the market, having been used in many similar applications. Renderoc DS is fully compatible with all anode systems due to its low resistivity. This is true for a majority of the Renderoc range, meaning it can be use alongside cathodic protection. Renderoc HB45 hand applied mortar was also used where access was limited. Each phase of the repairs lasted approximately 2 weeks, involving breakout, continuity tests, anode installation, area preparation, spraying, and a 3 day curing period before moving onto the next section.THE BENEFITSThe corrosion and potential spalling of the existing concrete meant that there was a risk to health and safety of the bridge. If left unrepaired this could have also affected the capacity of the asset on a major UK motorway. The application process for each section of the repairs was significantly faster due to the spray application method and ensured a comprehensive restoration of the entire structure. Volker Laser completed all works on time and to program.

THE PROJECTKirriemuir DSR (Distribution Service Reservoir) is located close to Backwater Reservoir in a relatively remote area of northwest Angus, Scotland. The reservoir supplies the populations of Angus, Dundee, parts of Perth and Kinross with drinking water. The DSR is essentially a large water tank with an exposed roof which is vulnerable to erosion and wet weather damage. It is one of many DSRs in Scotland managed by Scottish Water. Morrison Construction appointed the Fraser Bruce Group as a specialist installation contractor to deliver the refurbishment of several Scottish Water tanks as part of a five-year framework involving civil engineering works. The Fraser Bruce Group have had an excellent working relationship with Fosroc for well over 30 years, so they approached the team at Fosroc to provide a selection of waterproofing solutions for different applications across the framework. They were looking for a robust yet flexible waterproof coating that would maintain its integrity for at least 20 years.THE SOLUTIONFosroc specified their most robust deck waterproofing system Nitodek FS System 3, with an additional topcoat for extra robustness against the effects of weathering. Nitodek FS is UV and slip resistant, and comes with the quality assurance of a 20-year warranty. It is also seamless, eliminating the risk of ingress through failed lap joints. For this application, the existing failed waterproofing system needed to be mechanically removed prior to the mechanical preparation of the concrete deck, after which the Nitodek FS system was applied. Once the existing system was removed, it was apparent that extensive concrete repairs would be required to both the perimeter upstand and the access hatch upstands. Spalling, delamination and blistering could be seen on various areas of the surface. Repairs to these areas and the 45⁰ fillets where horizontal meets vertical, were carried out using Renderoc GP. Once cured, the deck waterproofing phase using Nitodek FS was undertaken.THE BENEFITSBy using the fast setting, liquid applied Nitodek FS for the tank waterproofing system, the Fraser Bruce Group were able to take advantage of the 60-minute cure time to quickly apply the primer, fleece reinforced membrane and topcoat. This kept project costs to a minimum for the client, while the ability of Nitodek FS to bond to itself gave the additional flexibility of enabling the work to be completed in two stages, several weeks apart, with no risk of failure at the point where the two application areas met.

Old Meldrum DSR using Renderoc HB45 and Renderoc Primer for concrete repairs. Nitodek FS was used for waterproofing the outside of the tank and Nitoseal MS600 to seal the joints.

THE PROJECTThe One City Park development, designed by architect Sheppard Robson, is being built on a former police HQ site, is the first Grade A office scheme delivered in Bradford city centre for 20 years to address the need for high-quality offices. As a five-storey high rise building, the basement required an effective below-ground waterproofing solution to the main building core that would be fully compliant with the client's requirements and the relevant codes of practice and stand the test of time. The main contractor for the project, Caddick Construction engaged specialist concrete contractor Howard Civil Engineering for the basement build who then contacted Fosroc for assistance in producing a tailored waterproofing specification solution that would address the requirements of the project. As a trusted supplier of building materials and technical specification advice, Howard Civil Engineering has utilised Fosroc’s products for many other projects previously.THE SOLUTIONFosroc specified a full product solution for installation in accordance with BS8102 supported by a fully detailed waterproofing design provided by Waterproofing Design Services Limited. This included one of Fosroc’s innovative self-healing Supercast CWA product – crystalline waterproofing additive for concrete, Supercast SW20 and Supercast SWX waterstops in conjunction with Proofex Engage waterproofing and Proofex Total damp proof membranes. Materials were available to order ready to commence installation when required.THE BENEFITSThe main core works and basement project element is now complete, allowing the next construction phase to continue. Fosroc’s Supercast CWA will allow any small cracks to ‘heal’ with free lime crystal before they create damp problems, and the tough damp and water proof membranes will protect against ground gas, chemicals and corrosion. As the Fosroc products are designed to work together, a truly reliable and robust solution is delivered that keeps long-term costs of repair and maintenance to a minimum. Additionally, the contractor was able to access high quality technical advice from specification through to application, allowing them to mitigate potential problems and delays before they happened.

Prospero Ansty Park using Nitoflor Lithurin E.

Fosroc used Nitodek FS to resurface the walkway of Glasgow's 'Squiggly Bridge'.

Fosroc used Nitodek FS to resurface the walkway of Glasgow's 'Squiggly Bridge' resulting in a safe, long-lasting and easy-care finish.

THE PROJECT The Stephen A Schwarzman Centre is a new state-of-the-art performing arts and exhibition development that will house the University of Oxford’s Humanities department. The architect, Hopkins, is well known for designing environmentally efficient buildings, and the main contractor Laing O'Rourke has a wealth of experience of building large complex structures. Fosroc was invited to provide a full waterproofing system for a two-level basement due to their technical expertise, customer care, and proven products. Three forms of waterproofing were proposed; pre-applied membrane, waterproof concrete and a cavity drain system. The project also included a complex detail where the new basement needed to punch through the secant wall into an adjacent basement. THE SOLUTION Fosroc entered into an early design development phase with Laing O'Rourke to progress the waterproofing design and overcome some of the particularly challenging aspects of the scheme. Design meetings were held to address these issues in advance of the scheme going to site. The primary protection proposed for the base was the robust Type A Proofex Engage pre-applied fully bonded membrane. Its unique mesh system allows a full bond to concrete and prevents water tracking between the concrete and membrane. Type B watertight concrete containing Supercast WCP – an integral hydrophobic pore-blocking admixture was used as secondary protection for the base and primary protection for the walls. Secondary protection for the walls was provided by the Type C Proofex Cavitydrain drained cavity system, that channels water ingress into the basement drainage system. Laing O’Rourke then appointed Fosroc’s in-house design service WDS to complete the design with the required professional indemnity insurance cover. WDS has delivered a fully detailed coordinated set of design drawings to detail the waterproofing installation, helping Laing O'Rourke to complete to the very highest standard. THE BENEFITS Fosroc were able to calculate approximate quantities for the scheme, including all ancillary items. This, coupled with a planned project programme enabled the supply of materials to be accurately scheduled, avoiding delays and improving the level of cost certainty for the client. By using the three types of protection, the basement of the four-storey academic building is afforded the maximum level of long-term protection against water ingress. The installation team have been very satisfied with the design provided by WDS, and the products and service received from Fosroc throughout the installation.

West Suffolk Hospital case study using Renderoc HB and Renderoc FC.