As demand increases to reduce build times, designers are sidestepping traditional methods of constructing exterior and interior walls in favour of composite panel systems, which significantly reduce build times, claims Denis Beardmore, Managing director of Paroc Panel System. B&E hears how the latest generation of composite panel systems can considerably improve the performance of completed buildings.

THE SPEED of build of large-scale buildings is extremely important in managing build costs effectively. Ensuring buildings are operational as quickly as possible to re-coup construction costs is a key consideration for architects and specifiers. They are demanding building products that offer fast build times, reduce defects and create better performing buildings that are efficient to run.

This demand has served to drive forward innovation in composite panel technology. As offsite manufacture techniques and added-value products have been developed, architects and specifiers have used the build and performance benefits of composite panels in many different types of development, including industrial and commercial facilities, as well as schools, hospitals, leisure centres and other communal buildings.

Finding alternatives

Traditionally, blockwork has been used in the construction of most of these buildings, however, high performance composite panels are increasingly being used as an alternative as they enable faster construction of exterior cladding and interior walls and ceilings. These panels are delivered to site in large, factory-manufactured sections, ready for installation and, as they are inherently strong, they can span over 8m without secondary structural support, significantly reducing materials and time on-site.

To further reduce build times, advanced manufacturing techniques are now also being developed that enable internal and external finishes, such as plasterboard and brick slips, to be fitted to the panel, or even entire room sections, in the factory.

As well as developing technology to speed up the on-site build process, high performance panel systems are also being developed to improve the performance of completed buildings.

For example, thermally efficient composite panels manufactured using high quality mineral wool can achieve a u-value of 0.16W/m2K, which exceeds the requirements of Part L of the Building Regulations. This considerably reduces heating costs, as well as CO2 emissions. Another area where composite panels can provide added value performance is sound absorption. In many cases, acoustic screens or boards need to be used to control sound in environments where high levels of noise are generated. However, specially designed panel systems can negate the need for these additional systems, combining high levels of sound absorption within the interior wall or ceiling
structure.

In particular, however, there has been considerable innovation in the area of fire performance.

Panel Performance

Following a series of very costly fires in the 1990s, building insurers became wary of composite panels. As a result, they took a broadbrush approach to insuring commercial and industrial buildings, in particular, that were constructed using this build method, which led to higher premiums across the board. Keen to address the issue, the building industry took a much closer look at the design of large commercial and industrial facilities and the fire performance of composite panels, in particular. In-depth investigations were carried out to ascertain the precise performance of different panel systems in a fire to provide a better understanding for insurers, as well as building owners, designers and the fire service, on what levels of fire protection can be achieved.

Studies revealed that a composite panel’s fire performance is largely dependent on the core material it is made from, the most common of which include extruded polystyrene, expanded polystyrene, polyurethane, polyisocyanurate and mineral wool. Various tests have shown that mineral wool, which is made from stone and will not ignite or burn, and is classed noncombustible, is a better performing core material in a fire.

With a better understanding of the fire safety performance of different composite panel systems, insurance companies now take a more holistic approach to assessing buildings constructed using this method and consider a broad range of risk management factors.

Elements such as building design, passive and active fire protection and effective site management are closely evaluated, which makes choosing the right type of composite panel that delivers the best possible fire performance vital in keeping premiums to a minimum.

Innovative Design

It is now widely accepted that mineral wool delivers the best fire protection and is, therefore, the ideal core material to construct panel systems. However, this performance can be further improved with innovative panel design, in terms of the quality of the mineral wool itself, as well as how efficiently the rest of the panel is manufactured.

Independent, specialist fire testing organisations will test a composite panel’s performance in a fire to allow building owners, designers and insurers to make meaningful comparisons between different systems.

There are two standard fire performance tests that are commonly carried out. They include the insulation test, which measures the length of time before the external face of a panel reaches an average temperature of 140°C when the internal face is exposed to fire, and the integrity test, which measures how long the integrity of a anel can withstand fire.

High performance mineral wool based fireproof panels have now been developed that will maintain their structural integrity in a fire for over six hours and insulate against heat for four and a half hours. As such, these systems can be used to create fireproof internal walls and ceilings that will contain a fire in one area of a building, completely protecting equipment in the next room.

Innovations such as these are revolutionising the build process and the way in which architects and specifiers are thinking about composite panels. The fast build times, added value performance and design versatility of modern panels are increasing their popularity and broadening their appeal for many different project types. I think this trend will continue, and manufacturers are already developing the next generation of composite cladding panel system.