The Series 91 - Supporting the weight of expectation

Selectaglaze traditionally offers the Series 90 for treating the ‘Monumental’ style sash windows found in grand Victorian and Edwardian buildings. However, the windows in an ongoing project exceeded the operational limitations that Selectaglaze would normally consider safe. Selectaglaze, therefore, set about finding a solution, and the Series 91 was born.  The Series 91 is derived from the already successful Series 90 heavy duty vertical sliding unit but with strategic frame modifications and the introduction of high-capacity spring balances, allowing it to safely operate to even larger sizes. The maximum carrying weight of a Series 90 is 65Kg. The Series 91 however, can hold a maximum of 100kg in sash weight thanks to increased section sizes that are larger, and more robust.  The Series 91 vertical sliding unit was developed for several very large single glazed sash windows in a colossal project at an Edwardian Baroque building in London’s Whitehall. Averaging each at 4.5m x 2m and weighing in at around 200kg; installation is being undertaken in phases, with the frames polyester powder painted in a high quality metallic bronze finish. Working closely with the main contractors, Selectaglaze is fitting the bespoke measured perimeter frames first, followed by the huge secondary sliding sashes phased to be installed at a later date. This ensures the main contractor has maximum access to the reveals and primary windows for ongoing refurbishment, decoration and cleaning. Series 91 bronze polyester powder painted aluminium frames with low tac tape protection prepared at the Selectaglaze factory, ready to be transported for installation.   The existing single glazed primary sash windows were originally built to a very high standard and have now been refurbished. The addition of the new Series 91 secondary glazing units will significantly improve the sound insulation performance which is predominantly what the existing primary windows required. The original acoustic report identified significant noise issues due to the large volume of traffic, buses and HGVs around the building which clearly had the potential to disturb occupants within the guest rooms and private apartments.   Series 91 aluminium frames and timber surrounds installed during the first phase of the installation.   The standard opening mechanism for the bottom sash on the Series 90, utilises our recessed finger pull where the operator can insert their fingers to lift it. However, due to the weight of these gigantic sashes, a bespoke handle design was required for the Series 91 to ensure greater hand purchase could be obtained to help move the panel. This has subsequently been created by our in-house design team and a physical sample is in development specifically for this project.   3D modelling of the new handle in development for the Series 91 vertical sliders  Selectaglaze has worked closely with the architects and the main contractor to develop and overcome a variety of challenges on the project and expects to complete installing 63 Series 91s for this project by the end of this year; 51 of which are glazed with 10.8 glass and the remaining 12 units with 6.8 glass. This is just a fraction of the secondary glazing due to be installed in what is envisaged to be the company’s largest job to date.