Acid etching to give traction

NO SLIP: Whangarei District Council field officer Grant Alsop (left) and Nadia de la Guerre check out pavers at the corner of Rathbone and Cameron Sts that will be acid etched in the next month. PHOTO/MICHAEL CUNNINGHAM

Safety plan for slippery pavers

Whangarei District Council staff have got to grips with the slippery paver problem in the city centre and decided acid is the answer to making footpaths safe.

So contractors are expected to acid etch all pavers needing treatment by the end of next month, readying footpaths for winter and the future without any repeat of the fall that broke 66-year-old amputee Wayne Wheeler's hip when he slipped over in Rathbone St in December.

After the fall, it was disclosed the WDC had received only four official complaints about slippery pavers in the previous six months.

But the paver danger was highlighted by comments from Northern Advocate Facebook followers. Within 48 hours of the story of Mr Wheeler's plight being posted, more than 900 people had something to say about it, most of them claiming to have also slipped on paved CBD footpaths.

Whangarei Mayor Sheryl Mai acknowledged the problem, saying: "I have directed staff to find a solution to this safety issue, even if that means replacing the tiles."

Replacing pavers throughout the city centre would cost an estimated $800,000 to $1 million, WDC infrastructure technician Nadia de la Guerre said.

However, the acid etching solution is expected to make the footpaths safe for about $80,000.

Tests showed acid etching of pavers on the south side of Rathbone St produced better adhesion for people's feet than anti-slip material applied to the footpath on the opposite side of the road.

Sandblasting produced even more satisfactory adhesion, but WDC waste and drainage manager Andrew Carvell said sandblasting pitted the ceramic surface of the pavers and it was feared the small holes could fill with material which would make the pavers greasy in wet weather.

The pavers sandblasted in a laboratory for the tests are to be placed by the roadside on the corner of Cameron and Rathbone Sts and their condition monitored for two years to see if the suspected deterioration takes place.

Experts from Opus International Consultants' Whangarei laboratory used a British pendulum tester to assess the paved footpaths at 18 sites in Rathbone, Cameron, James, Bank and Vine Sts earlier this month. Bank and Vine Sts passed the tests with flying colours, their adhesion far higher than the required standard. Mr Carvell said their footpaths had "different bricks" to the other streets and didn't need acid etching.

Five of the 16 sites tested in other streets scraped in with a pass. Of the 11 test sites which failed, the corner of Cameron and James Sts was by far the worst, with three Rathbone St sites also well short of satisfactory.