The 4th and 5th floors are currently being refurbished at Devon House and Structural Renovations have been employed to carry out the concrete repairs.
Devon House is situated on Great Portland Street and is part of the Langham Estate portfolio.
The floor slabs have been constructed from clinker concrete and steel filler joists. The filler joists have corroded and caused the concrete and plaster to crack and spall.
The defective concrete was removed from around the filler joists, the corrosion was removed by mechanical wire brushing and then the cleaned steel was primed with two coats of Fosroc Nitoprime Zincrich Plus. A galvanised mesh was fixed over the exposed steel and the concrete was reinstated with Fosroc Renderoc HB.
Structural Renovations have been working at Hallam House on Hallam Street since late 2018. The building is part of the Langham Estate portfolio and we have been working closely with the Estate’s Principal Contractor, Millane Contract Services and the Consulting Engineer, Jacobs.
The building is currently being refurbished and upgraded. In the basement plant rooms and brick vaults we have installed a new waterproof render using Flexcrete materials. Concrete repairs and anti-carbonation coatings have been carried out within the rear lightwell to the window heads and cills.
Internally, the existing lift was removed, and we were required to carry out extensive repairs to the staircase that wraps around the lift core. Existing supporting steel work was cut out and the landings and strings were repaired back to the original surface profile as required by the contractor installing the new glass lift.
Structural Renovations have secured a 12 week project to remove brick slips from a 5 storey purpose built office block in Hove, known as Preece House.
The structure was built in 1980 when the fixing of brick slips (thin sections of brick) was still a relatively popular design feature. This gave the impression of an entirely brick built building, when in fact the slips were adhered, using mortar over the floor plate edges to conceal them, a little like tiling.
Over time the mortar used to affix the slips can fail, either through poor preparation at time of construction, or freeze/thaw activity, if moisture has penetrated behind them. This can lead to failure and the slips falling from the building, causing a significant health and safety risk.
Following a diagnostic survey earlier in the year it was identified that a significant amount of brick slips had failed or were beginning to fail. At this time the building was made safe by removing all loose slips, to reduce the risk to people or property.
A number of remedial actions were considered and in October the decision was taken to remove all brick slips from the building, thus removing the health and safety risk altogether.
The majority of the works is being carried out from scaffolding, which due to the shape of the building is cantilevered in places. Low level areas are being accessed from lightweight aluminium mobile towers.
Following the brick slip removal process, the exposed reinforced concrete substrate is surveyed, to identify if repairs are required. These are being carried out using Flexcrete Monomix, as part of their proprietary concrete repair system.
Once repaired we are contracted to apply Monolevel FC (fairing mortar), followed by the application of Flexcrete Monodex Ultra (pigmented anti-carbonation coating).
Associated works items, such as replacing perished sealants and localised repointing have now also been instructed and it is anticipated that the works will complete in mid-February 2019.
Structural Renovations secured a further phase of concrete repair work at the Barbican Estate in June 2018. The works include the 3No. tower blocks, 11No. terrace blocks and 9No. underground car park areas.
Similar to previous phases that Structural Renovations have completed the works involve repairing defective bush-hammered and fair-faced concrete surfaces, using specialist hand-placed mortars, approved by our client, the Corporation of London and English Heritage.
In additional we are contracted to complete resin-injection to seal ongoing leaks from podium areas, together with the installation anodic protection, to control corrosion within the buried steel reinforcement.
The works are being accessed by various means, including abseiling for the towers and terraces, scaffold for isolated structures and lightweight aluminium mobile tower within the car parks.
The entire estate is Grade II listed due to it being one of London’s principal examples of Brutalist Architecture but meaning any necessary repairs are to be carried our sensitively, so as not to detract from the original design ethos of the architects, Chamberlain, Powell & Bon.
The project is due for completion in May 2019.
Structural Renovations will shortly be completing a 6 month contract to repair and protect the external elevations of this very large and impressive building, constructed between 1909 and 1911 in a style of architecture known as Beaux Arts.
Originally built to house the GPO Money Order Office, it was sold in the 1990’s by the Royal Mail for redevelopment and converted in to 190 flats in 1994. The building is now recognised as one of the most important in the area.
Our works have included surveying all concrete and render surfaces to establish the condition, followed by carrying out sympathetic repairs using polymer modified mortars. All areas have then received a primer followed by 2 applications of a pigmented anti-carbonation coating to protect the structure from the atmosphere.
In addition to the repair and coating works a significant amount of the original Crittal windows have been replaced to an approved design that the local authority has been closely involved with, to ensure that this significant example of an architectural style more likely to be found in France (Ecole des Beaux Arts, Paris), or further afield in the USA (Grand Central Station, NYC). The windows that haven’t been replaced have been redecorated along with all other existing metalwork, guttering and rainwater pipes.
Furthermore the roof level ‘pods’ have been waterproofed using Sika’s Sikalastic 625 and a number of terraces waterproofed with Sika’s Sikalastic Rapid 721.
In early May Structural Renovations were employed to carry out emergency repairs to the reinforced concrete at Carnival Pool in Wokingham.
The leisure complex was constructed in the early 1990’s and following a detailed survey of the undercroft areas of both the main and learner pools it was established that extensive repairs would be required to the supporting beams, soffits, drainage channels and external walls of the pools.
The complex is planned for redevelopment in 2020 but in order to keep it operational until then a repair scheme had to be implemented that would provide the required protection in an aggressive environment.
Working closely with the local authorities consulting engineer it was agreed that defective concrete would be removed and any exposed reinforcement treated prior to reinstatement with a polymer modified repair mortar. In certain locations where the warm, moist atmosphere, combined with chemical attack was most likely to accelerate the deterioration of the concrete a migrating corrosion inhibitor (MCI) was applied.
Additional works instructed included waterproofing the drainage channels, both internally and externally, using a thixotropic modified polymer coating, complete with an embedded elastomeric composite tape.
This 6 week project was completed on time and due to careful programming the public parts of the complex were required to be closed for only 2 of those weeks.