Saint-Gobain Weber’s External Wall Insulation (EWI) system has been selected by Rotherham Metropolitan Borough Council (RMBC) for a property renovation project of 37 Dorlonco system-built homes in the Rawmarsh area of the town.
Rotherham Council awarded the main contract to Keepmoat who sub-contracted the EWI application to specialist applicator Hamilton First.
The weber.therm XM EWI system specified for these homes uses 50mm phenolic insulation panels fixed to the external substrate, which is covered and protected by theweber.rend RB Render Brick finish, a combination of two coloured mortars used together to create a brick-effect finish.
Once the insulation material has been fixed to the structure, an initial coat of weber.rend LAC render is applied over the insulation with a mesh-cloth reinforcement laid into it.
A second pass of weber.rend LAC is then applied which is finished with a lightly comb-scratched surface to encourage the bond with the weber.rend RBB base coat which acts as the mortar line. This is applied at 7-8mm thick and ruled to achieve a flat, in-plane surface.
When this has taken-up a 2-3mm coat of weber.rend RBF face coat is applied and the surface lightly textured with a soft bristle brush to create the brick face. When this coat has taken-up, the brick pattern is marked carefully and cuts are made through the face coat render to expose the base coat to achieve an authentic, bonded brickwork appearance.
The company says the new system has greatly improved thermal performance while at the same time changing the streetscape for the benefit and wellbeing of the residents.
A target U-value of 0.29W/m²K has been achieved from a pre-installation U-value of 1.05W/m²K. Four different colours have been used, some in combinations to match the duo-tone of the original facade, using Chestnut, Fallow, Umber and the new Georgian Red.
Additionally, a distressed finish has been achieved by artistic application of weber.sil P, a silicone enhanced masonry paint, to create an even more natural, aged brick effect which has been enthusiastically received.
James Hamilton, of main contractor Keepmoat, commented: “Everyone at Rotherham is delighted with the visual results that retain the traditional community look and aesthetics; the residents are really happy with the much improved comfort provided by the insulation which has made their homes warmer and their bills lower. The quality of the Weber EWI system is first class and together with the skills and experience of our application contractor, we have achieved an excellent result on the Rawmarsh homes.”