Jungle formula

So awe-inspiring is the transformation of the interior of St Pancras’s Victorian shell that travellers may not notice what they’re walking on. But if you do find yourself in the arrival or departure areas of the new Eurostar terminal, take time to admire the floor: it’s made from thousands of blocks of Jatoba wood from the forests of Brazil.

This was a once-in-a-lifetime project for Atkinson & Kirb, which supplied the blocks, and for flooring contractor Loughton Contracts. From sourcing the timber, to manufacturing the blocks, to preparing the floor, to laying the blocks, the job was a challenge, described by Atkinson & Kirby’s sales and marketing director David Ellams as ‘one of the most complex manufacturing tasks we have ever undertaken’.

Task number one was sourcing the hardwood from a sustainable source certified by the Forest Stewardship Council (FSC).

‘We were really unsure whether we would be able to supply that amount of FSC-accredited Jatoba,’ says Ellams. ‘We put forward a couple of alternatives but both were rejected.’ The architect, Chapman Taylor, had been inspired by the floor at Copenhagen airport, which is made from the same wood.

Despite the challenges, Atkinson & Kirby sourced the timber necessary for the 6,000m2 of floor through one of its importers in Belgium. There were visits to Belgium and to the firm’s factory in Ormskirk, Lancashire from the FSC, Chapman Taylor, Loughton and the main fit-out contractor ISG to check the lumber once it had arrived.

It took some time to decide on the optimum size of the blocks. The problem was in creating room for the wood to expand without putting expansion joints through the floor. The solution was to leave 0.6mm gaps between each block, with block sizes of 980mm x 68.8mm for the long thin pieces and 675mm x 69.4mm for the cross pieces which together form the ‘ladder’ pattern of the floor. ‘The tolerances were pretty damn tight,’ says Ellams.

Quality control was also tight. Each block was individually measured and examined to ensure it had no flaws.

Meanwhile, Loughton was preparing the floor, a £2m job itself (the Jatoba flooring contract was £1m). The contractor had to install 1,300 air diffusers which had to be positioned accurately in three dimensions, breaking out concrete to install manhole covers and floor boxes and laying a fast-curing screed over the concrete sub-base.

Loughton sales director John Collier says the firm’s knowledge of client CTRL’s quality control systems, gained while working at Stratford and Ebbsfleet, stood it in good stead. ‘We had experience of the paperwork trail that was part of the contract,’ says Collier. ‘The paper drives the job.’

Logistics were the next challenge. Atkinson & Kirby had to book its delivery slots three days in advance and time them so that the pallets of blocks could be unwrapped and allowed to acclimatise for at least a week before Loughton laid them.

Loughton had 50 men on site, including 20 laying the wood, many of whom came – appropriately – from a Brazilian flooring gang. Time was tight and Loughton had to work long hours to accommodate other trades on site. ‘The secret for us was having the right management on site,’ says Collier. ‘We put our best guys on that job. We couldn’t be late: it had to be ready for the Queen on 14 November.’

The floor has been designed to last. Usually the location slots come 6mm below the surface of the blocks but at St Pancras they are 10mm down to allow for more wear. And rather than being laquered, which would show up patches of heavy use, this floor has been treated with oil, which is reapplied regularly as part of the maintenance regime. This has been used at Copenhagen Airport and has proved successful.

There were teething problems with the floor, says Collier. Too much water during maintenance caused damage which Loughton had to go back to repair. But the problems have been sorted out.

If the floor lives up to its design life, it will be there for the next 50 years. So if you haven’t seen it yet, there’s still time.