If you’re flying in to or out of Auckland, keep your eyes peeled for what is believed to be the World’s Biggest advertising sign on a roof.

Supermarket chain Big Fresh has painted the sign on the roof of its Manukau City national distribution centre and support office which lies just off the flight path of Auckland International Airport.

The supermarket chain has advised the Guinness Book of Records of the attempt and is awaiting confirmation of the record. The sign was completed in May of this year.

It comprises the Big Fresh company logo and more than 2,690 litres of specially imported grey primer and yellow and green top coat have been utilised in painting the sign.

The sign itself measures 145 metres long and 48 metres high with the upper case letters being 30 metres high.

Big Fresh brand manager Peter Garwood said the idea came to him one day when he was flying in to Auckland airport after a business trip. "The roof is so clearly visible, I began to wonder how well it would stand out with the logo on it to promote our brand," he said.

Mr Garwood said New Zealand immigration figures showed some seven million domestic and international passengers flew in to or out of Auckland airport every year. Two and a half million of those had window seats!

For signwriter Tony Reid and his assistant it was hardly an everyday job. They were on the roof at 6.00am each day in February and March in an attempt to beat the worst of the summer heat. Most days they had to leave the roof by 11am as it got so hot.

"The temperature got up to around the mid-40s (on the roof) sometimes," he says. "We wore surfers’ rash shirts hosed down with water so that any breeze added a chill factor to help keep our body temperature down."

During one hot spell, Mr Reid was temporarily stricken with sun stroke. Other obstacles were bird droppings and dew, both of which had to be cleared daily before painting could begin.

"Another difficulty we had was the size of the sign and our close proximity to it," Mr Reid said. "It was hard to get a decent perspective on it. Even though we followed a grid pattern it was still hard to see if we had everything properly lined up. It’s a little difficult to take a couple of steps back to admire your handiwork."
 

The current record for an advertising sign on a roof is 2,164 square metres held by a company in the United Kingdom. So just how big is the Big Fresh sign? Allowing for the curvature in the design, and the fact that some lettering is on an unpainted background, the Big Fresh sign covers 4,500 square metres - more than twice the size of the existing record holder. Should they ever choose to paint the rest of the background on the roof, the overall size of the sign would be in the vicinity of three and a half hectares!

For the technically minded, the sign was created by identifying the mid point in the 175 metre width of the roof structure on a horizontal plane. A measurement of 72.5 metres either side of the mid-point was marked, to identify the outer limits of the area to be signwritten. The lay of the galvanised roofing material provided the perpendicular reference for marking the letters out.

Using this scale, and knowing that the roof was some 200 metres deep at the widest point, Tony Reid created a 1:100 scale grid and projected the proposed sign onto the grid in the normal fashion and afterwards transposing the measurements to the roof itself using green spray bombs to mark out the perimeter of each letter. The semi-circle was marked out in yellow spray bombs after Tony used a 45 metre length of rope anchored at the mid-point. A horizontal reference point occurred naturally where the roofing iron screws connected to the purlins. From there on it was just a case of ".....playing connect the dots," according to Tony.

The three different paints for the roof were made in three single batches. The primer was specifically formulated by Solver in conjunction with Broken Hill Pty who use it for their ‘long run’ galvanised roofing and is water based ‘Galvalink". The top coat is Solver Briteglo acrylic exterior gloss.

In preparing the area to be painted Tony and his assistant washed the entire area using a yard broom, water and a non-ionic detergent as specified by the paint manufacturer. This was sluiced off in one operation after scrubbing. Paint was applied using an airless spraygun powered by a petrol driven compressor pumping at 2,500 to 3,000 psi. Custom made extension nozzles to the spray guns overcame the need to stoop to apply the paint.

The cost of the paint alone was $28,000 and at the end of the job a 4 litre can of unmixed yellow paint remained along with 4 litres of unmixed green.