Dutch company PreFab Limburg has developed a system that drastically reduces the depth of floors and, it claims, can cut construction costs by 10 per cent. Called Infra+, it inverts the usual structure of a floor, putting the concrete slab below the steel beams rather than above them. The lower flanges of the beams are set into 2.4m-wide planks and supplied to site as a single prefabricated unit. The floor itself consists either of a standard floor deck supported on a framework or a floor finish with a cement or anhydrite base on a profiled steel plate. Services run within the zone defined by the steel beams, which have holes within them to allow transverse floor runs.
The underside of the concrete floor forms a finished ceiling, and there is no need for a raised computer floor. In this way, claims the company, the total floor depth can be reduced from a 'typical' 800-1,200mm to only 400mm. This involves several assumptions. On the one hand, it presupposes that there was no interest in putting the services in the structural steel zone of the 'typical' floor through the use of castellated beams. On the other, there is the supposition that the client will accept the exposed concrete soffit and the compromises that will have to be made in terms of lighting and ventilation. PreFab Limburg is looking for a distributor in the UK. E-mail aplus@plex. nl