WEBER.THERM XM EXTERNAL WALL INSULATION BY SAINT-GOBAIN WEBER TRANSFORMS COVENTRY CROSS ESTATE
The current phase of regeneration at Coventry Cross Estate, which commenced in 2011, comprises 160 flats across four blocks which are arranged around a central open space flanked by resident parking. It has a scheduled renovation budget of £5.5m. It is part of Poplar HARCA's five-year programme to bring a quarter of its 8,500 housing stock up to modern homes standard working to a regeneration budget valued at £145m which has been running successfully for the past three years.
The Coventry Cross project initially included replacement of kitchens, bathrooms, fenestration and doors; repair and alterations to walkways, balconies and site amenities as well as a new façade to the buildings which would collectively bring them up to the government's Decent Homes Standards. It was Durkan, together with the London-based architect Baily Garner, who promoted the complete delivery of thermal insulation and render application that would totally transform the visual aesthetics of the properties for the benefit of the residents, local and visiting community while contributing to the greatly improved thermal performance of the dwellings. Baily Garner completed a full standard assessment procedure (SAP) to establish their energy performance.
Poplar HARCA was formed by the London Borough of Tower Hamlets in 1996 and the first properties were transferred in 1998. In subsequent years the property portfolio grew to 8,500 homes when the Secretary of State authorised the transfer of Coventry Cross to become part of the estate in 2007.
The apartment blocks were constructed in the 1960s using cavity brickwork and precast walkway concrete sections. Limited insulation has meant high energy consumption in these dwellings which has become daunting to tenants' as fuel costs continue to soar. The HighHpriority to substantially improve the thermal insulation of the properties determined that EWI was essential and the weber.therm XM EWI system was specified. Saint-Gobain Weber surveyed the structures and a target U-value of 0.35W/m²K was established. This has been achieved with the application of 80mm thick mineral fibre insulation on the main walls and stairwells, and 50mm of phenolic insulation on the upper walkways.
The energy efficient retrofit is expected to cut residents' energy costs by as much as 25% while achieving greater comfort, reduced energy consumption and lower carbon emissions. In real terms, the Stanborough block of 28 flats, soon to be completed, should see the energy performance grade rise from an un-impressive E to a comfortable C grade. As the insulation is applied to the exterior of the building there is no loss of internal space and minimal disruption to residents.
The Saint-Gobain Weber recommended specialist applicator Primars has carried out the insulated render application following structural repairs to the concrete walkways using Saint-Gobain Weber concrete repair products. The weber.therm XM EWI system requires the insulation panels to be mechanically fixed into the brick substrate using a brickbond pattern to overlap the joints. The first application of 6mm weber.rend LAC is applied followed by the meshcloth reinforcement which is encapsulated in another coat of render to form a 12mm total coating. The final finish at Coventry Cross is weber.sil P, a silicone resin emulsion paint. This high performance paint has high water shedding properties, high vapour permeability and provides a long-term, low maintenance finish and is available in a wide colour palette. At Coventry Cross white and two tones of grey were selected to balance the exterior decor whilst the vivid colours offered by weber.plast TF 150 were chosen for the balcony fascias. weber.plast TF is an acrylic based, composite decorative finish applied by float. The attractive weber.therm RB, which achieves a truly convincing brick-effect finish, has been used on attractive detail panels on 3000m² of the walls to add further texture and colour detail to these rejuvenated buildings.
The versatile and award-winning Saint-Gobain Weber EWI systems are BBA certificated and ideal for use in new build and refurbishment schemes regardless of size, height or exposure of the building. This is due to the system's market-leading fire performance, impact resistance and wind-loading capabilities. The unique weber.therm XP system with weber.therm M1 mesh-reinforced, One-Coat Technology, through-coloured render is quickly being recognised for its contribution to the reduction of programme works by up to 50%. These renders can be spray or pump applied reducing application times still further and allowing access for other trades even sooner. weber.therm EWI is Energy Saving Trust recommended.