Working in tandem with two of the manufacturers of the base material, Mecatiss Interact Fire Solutions has completed the R&D on a new approach to the use of cast epoxy intumescent for fire protection in the construction industry. By successfully removing the need for a wire mesh, whilst maintaining the structural integrity of the product, we can bring to market an exclusive product that will have dramatic cost savings and added aesthetic advantages.
How it all began ...
The medium of epoxy intumescent was originally developed for the offshore market to offer exceptional fire protection to structural steel. The properties of the material had to withstand the rigours of the North Sea in order to protect oil platforms for up to 3 hours in hydrocarbon fire conditions. The properties of epoxy intumescent—including chemical, impact and weather resistance—also needed to withstand jet fire blowouts and explosion. Such benefits have obvious application for many commercial projects, like hospitals, schools and prestigious office/retail projects. The explosion resistance means that important government and city institutions can also be protected against potential terrorist attack.
The development of cast epoxy intumescent—and the need for a wire mesh
An integral part of the system has always been the use of a wire mesh. This supports the intumescent when it has re-acted (i.e. intumesced or expanded) during jet fire conditions.
Interact's specialism is casting epoxy intumescent for cellulosic (i.e. normal building) conditions. This is most evident in their flagship product, Interactive Columns. Until recently, it was necessary to incorporate the wire mesh within the casting. The production method was limited, therefore, to a minimum thickness of 10mm to ensure material flow during casting. In addition, the fire test data was predicated on the wire mesh being continuous around the structure. In order to ensure compliance with the test data it was necessary to re-instate the continuity of the wire mesh within the two half-shells previously cut to allow for installation. This was done by fitting a wire tie (3 per l m around the casting following the installation of the casting) and placing it in the prepared groove.
The drawbacks of this requirement were both practical and aesthetic. From a manufacturing point of view, the wire mesh limited the length of casting to 1 – 1.25 m. This restriction was because the interference of the mesh creates a risk of air pockets forming. From the aesthetic perspective, the wire tie grooves required a substantial amount of decoration to conceal their presence. Mecatiss Interact has never claimed to be able to eradicate entirely the slight 'witness' marks created during this operation, and recommends a slightly textured finish to help conceal these minor imperfections.
Now, there's another way ... meshless!
Recently, the rule book has been re-written. Two of the four raw material manufacturers have re-tested epoxy intumescent specifically for the construction market. This major development has eliminated the need for any wire mesh—with obvious advantages to cast epoxy casings. Castings can now be made much longer and are only really limited to the strength of the mould used to form the circular casing. With no tying wire now required to achieve the necessary test data, the aesthetic benefits are obvious.
Mecatiss Interact have perfected the art—and now have their own manufacturing facility
Taking advantage of this revolutionary development, Mecatiss Interact have re-engineered the manufacturing methods to achieve a much more accurate, concentric casting which would have proved difficult with the wire mesh in. Manufacturing a casting which is two metres long, with no tying wires, means that a standard floor level installation will require decoration to dress just two vertical seams and one horizontal. Under the old method, there would be 11 horizontal grooves to dress, as well as the two vertical. Future development may result in eliminating even one horizontal seam, resulting in bespoke lengths to suit the site project requirements.
There are limitations, of course. For example, we do not advise that this length of casting should be used all the way up an atrium column. There are health and safety considerations to take into account when working at height. In such cases, we would advise that the installation should revert to one metre lengths following the first 3.5 metres.
Costs are reduced … and appearances enhanced
The effect on the cost of installation and the final look of the product are both significant. The cost of installation could be as much as 50% less than the previous method. The finishes available would be virtually limitless, in terms of texture or super smooth, offering an increased range to meet the demanding world of architectural design.
In order to protect and capitalise on these new innovations in cast epoxy intumescent, Mecatiss Interact Fire Solutions has managed to secure its own manufacturing facility. The experience gained in the casting industry means that Mecatiss Interact is guaranteed to provide the best solution to hollow section fire protection at costs which directly competes with many other costed alternatives.
Mecatiss Interact is keen to work with architects and specifiers to analyse costing alternatives—and show how the meshless product not only compares on price but also how it gives true integrity to the fire protection system. Mecatiss Interact will continue to embark on new research and development projects designed to maximise the use of epoxy intumescent by the passive fire protection industry.
For further information, please contact Mecatiss Interact Head Office direct
