Surface industry

High-rise living is once again back on the housing agenda with several British cities cultivating their own cluster of multi-storey residential towers. No longer linked with poverty, centrally-located apartments are the choice for young professionals seeking the high-life. Today’s tower block residents have more experience of Urban Outfitters and its range of fruit-squeezers than the day-to-day realities of urban deprivation.

Brought about through a confluence of government policy – which encourages brownfield, high-density design coupled with Part E sound regulations, this explosion of development has other winners too. Take the precast concrete hollowcore flooring market, for instance on average it’s grown by 8% a year since 2000.

About 50% of the hollowcore market goes into housing, mostly the upper floors in flats. The rest is split between industrial, commercial, car parks, offices, schools and hospitals. Until the apartment boom hollowcore predominated in the commercial and industrial sectors, for shops, offices and warehouses, but with the industry-wide development of 300kg units, giving additional density - and hence suitability for Part E its uptake has gone, well, if you’ll pardon the metaphor, through the roof.

The growth in the market is reflected in the fact that the top flooring providers are expanding their facilities. Bison, far and away the market leader in terms of production volume, has built a new plant at Swadlicote while Milbank, the fourth biggest producer, in a bid to establish a national presence, has built a new, highly-automated factory in Brandon, Norfolk, doubling its production capacity .

The Precast Flooring Federation (PFF)

lists Hanson and Tarmac as the other key competitors in the sector with Irish firms Creagh and Aitchison Glover also making inroads into the UK market.

Tarmac, number two in terms of sales, is also investing in hollowcore flooring, although there’s no sign of a new factory. Tarmac’s Phil Harris says: “It would require a huge investment for Tarmac to rival Bison for the top spot.”

John Duffy, a director of Hanson’s Building Products, says: “We’re investing in a new factory in the north east that will develop three new products; a lattice girder for use with composite floor systems, a two-way spanning slab for open-plan offices and composite wall panel system. [The factory] will be up and running next year.”

The total area covered by hollowcore flooring is difficult to ascertain because Bison has traditionally withheld its sales figures. Nevertheless, Paul Hobson, managing director of Milbank Floors, suggested an annual production figure of around 5.6m sq m. “Growth has actually receded in the past two years, reflecting the housing market slowdown.”

An industry insider suggests that Bison is way out in front with an annual output of more than double its rivals (see graph).

Despite its reluctance to discuss actual figures, the PFF volunteers the following prediction: “Expect Milbank to leap into second place when the Brandon factory goes fully operational. It’ll leave Hanson and Tarmac vying for bronze.”

If Britain’s love affair with high rise accommodation continues, as it surely must, the competition for medals among hollowcore’s leading manufacturers is set to become fiercer in coming years.

From factory floor to living room floor... and not a human in sight

In the quiet pine forests that surround the sleepy village of Brandon, bright yellow ‘robots’ go about their business, shuttling materials, extruding forms, printing data, lifting, cutting and removing. There’s not a human in sight.

The stage for this mechanical ballet is a vast, bright hall – more than 200 m long and nearly 40 m wide. Sunlight floods in through windows in the roof, a simple decking system supported on steel trusses. Everything else, however, is made from concrete: the floor, columns, the wall panels. And concrete is what concerns the “robots” that never seem to stop – they’re busy making precast concrete hollowcore planks for Milbank.

This thoroughly modern production facility is key to Milbank’s drive to become number two in the concrete flooring industry. As well as being low on manpower, health and safety focused and which uses several green and paperless processes, the factory is also a product showcase: it’s been built from Milbank components made in the factory next door.

“We can produce more than 300,000 square metres [a year] here, but have space to double that,” says Paul Hobson, Milbank Floor’s cheerful - and human – managing director. “When we’re fully operational, and have all the beds running, it’ll take our total hollowcore output over the 1,000,000 metres squared mark.”

The firm has another hollowcore factory in Earls Cone, near Colchester and previously it had focused its efforts on London and the south east.

But the Brandon base will allow Milbank to extend its reach and become a nationwide supplier. Marketing manager Steve Horton says Milbank can now offer a solution to contractors looking for fewer suppliers or perhaps even an exclusive one. “In the past we’ve not been able to do that; now we can,” he says. Orders for a job in Durham are already on the books.

The factory has eight 150 metre long beds installed, six of which are operational, with room for another four. It produces hollowcore planks with depths ranging from 150mm to 450mm deep. The casting, plotting and bed cleaning machines – the yellow robots - work in tandem with a bullet skip, the factory’s busiest servitor, that delivers the cement mix to a transverse skip that feeds the extruder. All the devices are computer controlled and pre-programmed to meet specific orders.

Automatic plotter

The planks are cured on the casting beds then cut into three sections, around 50 metres each, then lifted onto a sawing line using two heavy-duty gantry cranes. Before the lift however, a mobile plotter glides into place and begins printing order data and sawing guidelines. It seems to have a mind of its own. “It’s a bit like K9!” quips Jeremy Milbank, technical director, referring to Doctor Who’s robotic “dog”. Sensors stop it running into the casting machine and it picks up reflected light from the yellow jerseys too, explains Milbank, so it will never run into a manual operator.

The planks are then transported to an acoustic chamber where a diamond-tipped saw cuts angles as required. Throughout operations, a shallow channel collects and drives slurry - cement and water – back to a recycling unit that separates the two and feeds them back into the process.

After cutting, planks are removed to the yard and loaded onto A-frames, so orders can be picked up without the need for fork-lift trucks. And every plank is sequenced to be loaded in the correct order for removal and placement on site, thanks to a programme that converts customer drawings into “bed schedules” which drive the plotter and saw.

Milbank has a history of innovation and adoption of new technologies. A research trip to Europe in the 1940s resulted in the firm moving into precast production and away from its roots in building and undertaking. Hobson says that the group chairman, John Milbank, continues to travel abroad in search of ideas. “There’s no difference between work and play for John. If he’s on holiday somewhere, he’ll pop into the local concrete factory,” says Hobson.“ Apparently, the idea for the central sawing line was borrowed from a factory that was visited during a Swedish holiday trip. “John brought back a shakey video. The first half was of his feet but the second half, well, it showed the technology from which we developed our sawing line.”

The question remains however: why does Milbank not aim for the top spot? Why not be the biggest in the UK? Hobson is realistic: “We’d have to build a few more factories to catch the leader – Bison has four. For now, aiming for number two will do.“

It’s not hard to imagine a mechanical sigh of relief emanating from the robots in the factory hall at this – they’re already working flat out for that silver medal position.