Siderise MC Mullion Overclad

Innovation overview and development

An overview of the product
The Siderise MC Mullion Overclad is a decorative mullion liner designed to provide a simple yet robust solution for enhancing the acoustic performance, or acoustic and fire performance, of curtain wall facade systems. Hollow and lightweight aluminium mullions can provide an easy channel for noise to travel between adjoining spaces. The Siderise MC System is an external treatment that is installed over the top of curtain walling mullions where partitions abut. This substantially improves their acoustic performance, with acoustic only and acoustic plus two-hour fire rated versions to choose from. Suitable for both ‘stick’ and ‘unitised’ curtain wall facades, the system is ideal for projects where internal acoustic upgrades to the mullion are not practical. This includes situations where the internal layout is unknown during construction or when fit-out or operation has already begun. Its simple installation process allows it to be installed quickly with minimal disruption to occupiers, without the need to empty spaces of furniture, etc.

How the new product was developed, including effective collaboration, knowledge transfer and partnership along the project team
Since the 1970s, Siderise has been a global leader in the supply of high performance fire safety, acoustic and insulation solutions for a wide range of façade types. From the very beginning, our offering has been underpinned by a core value of “integrity in everything we do.” This means that we are not only committed to developing quality products which have been tested to rigorous industry standards, but that we stand ‘By Your Side’ at every step of the construction process, from the earliest design stages right through to building maintenance. This helps to ensure compliance, as well as to demonstrate commitment to safety and clarity.

Acoustic Engineers within the Siderise Group hold good relationships with Acoustic Consultants, who are very familiar with the full range of Façade Fire and Acoustic enhancement products that we manufacture and supply, it was repeatedly asked over the years if we did any products that could enhance the acoustic performance of ‘single mullion’ designs, they were familiar with our Siderise MI6 inserts, which are fitted inside the mullions, so can only be specified / used before the envelope was erected, but wanted a product that could be fitted externally post erection of the façade, additionally in recent times, something that offered additional fire safety benefits was increasingly sought, the idea for the Siderise MC was born.

Once development agreed, contact was made with acoustic, façade and fire engineers for market feedback on what may be required for such a treatment, acoustic performance, either a 1 or 2 Hour fire resistance, must be as environmentally friendly as possible, it should not have any through mechanical fixing into the mullion itself, be aesthetically pleasing and must be universal to suit a wide range of mullion sizes, 80mm-250mm as standard, quick and easy to install, and be able to accommodate some façade movement.
It was agreed that a sliding arrangement should be adopted, with a secret fixing method via the glazing and partition, the concept was use of a 6 part system comprising of retaining strips, one for the glass side, one for the partition, a male and female coverplate assembly and an acoustic or fire and acoustic infill behind, all parts were to be standard, only requiring a single cut to length, apart from the male cover plate, which would require both cutting to length and a possible trim to width, various designs were considered and in consultation with a metal fabricator the final design was completed and small prototypes manufactured and trialed in small mock-ups, final tweaks were made, then full size testing samples were manufactured. Acoustic testing at SRL and Fire testing at Exova were carried out, Technical and Marketing created the Brochure, TDS, MSDS, Fixing Guidance, Std Details etc, Patent and IP applied for to enable successful product launch 1st January 2022.

Leveraging the passive fire expertise from our sister company, Siderise Insulation, the Siderise MC successfully achieved a 2 Hour Fire Resistance EI, together with significant improvement in the sound transmission performance of a hollow mullion, typically achieving circa 24dB Rw empty and with the Siderise MC increasing to circa 44dB Rw, and with the Siderise MI6 included overall performance of 52dB Rw demonstrated that it did achieve the main needs identified in the initial development research to meet and exceed the potential requirements for BCO Guidelines for commercial and ADE for residential curtain walled projects.

How might this product have an influence on the specification
The product in the first five months since its launch has been specified on a very large number of projects, which was considered very encouraging given that this is a new product.

The Siderise MC offers a tested solution to widely accepted problems where a dedicated product has not been available previously and therefore having had to rely instead on non-tested adhoc / bespoke solutions up until now without the security of UKAS Accredited test evidence to support what the performance could be.

These specifications have originated from architects, acoustic consultants, fire engineers and contractors, and include projects in the UK, Europe, India and the Middle East, and should be supplied over the coming months / years, we have already supplied a number of UK projects, these include BP, Aberdeen, Microsoft, Cambridge, MU Allianz (Saracens Rugby Ground) and Sky Studios, Elstree.

Whilst most specifications have been for the standard stock system system, due to the simplicity of the system and Siderise ability to adapt to individual project needs for any quantity, we have worked with specifiers on nonstandard arrangements, these include special / unusual colours, anodized finish instead of PPC, larger width mullions than the standard 80-255mm, slimmed down option for the glazed partition market and even a project with glazing at 45 degrees.

How the product improved productivity in the process and/or quality and performance of the interior system
The Siderise MC having successfully achieved a 2 Hour Fire Resistance EI, and significant improvement in the sound transmission performance of a hollow mullion, typically achieving circa 24dB Rw empty and with the Siderise MC increasing to circa 44dB Rw, and with the Siderise MI6 included overall performance of 52dB Rw demonstrated that it did achieve the main needs identified in the initial development research to meet and exceed the potential requirements for BCO Guidelines for commercial and ADE for residential curtain walled projects.

Post launch, the product presentation and mock-ups have been shown to façade engineers, acoustic consultants, fire engineers, contractors and architects, the feedback so far would suggest that indeed the product addresses previously known common issues where sound bypasses the partition and reduces room to room performance via the hollow mullion, it has also highlighted that in recent years clients, architects and fire engineers have increasing concerns on fire safety regarding mullions abutting fire rated partitions, with the Siderise MC it has test reports for mullions up to 205mm x 50mm for 2 hours Insulation and Integrity and the recycled content, recyclability and Siderise’s commitment to always improving our sustainability in our manufacturing processes has been well received.

From an acoustic perspective, designs with twin mullions / vertical spandrel zones for horizontal sound transfer and/or twin transoms / horizontal spandrel zones have offered much higher levels of acoustic performance, and can be readily enhanced with use of acoustic and/or fire products in the spandrel zones, however with architects desire for clean lines, and large amounts of light from outside, use of single mullion or transom designs are becoming more commonplace in Europe, this leads to a single, relatively lightweight aluminium tube separating adjoining occupied spaces, previous methods such as extending the partitions past the mullions to the rear of the glazing have caused some issues with the plasterboard abutting the glass, including the internal aesthetics, the edges seen from outside, façade movement potentially breaking up the plasterboard, the latter requiring large movement gaps, which then degrade the performance, this could be enhanced at building design with the use of acoustic inserts, but this does not help if this is an existing building and/or a new build where the partition location is not known until post completion of the façade, so use of inserts are not practical, additionally no insert can upgrade the fire performance due to the thermal bridging of the aluminium.