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Volcanic rock and metal demands heavy-duty reinforcement

Fencing Solutions Waikato (FSW) were recently contracted by Livingstone Builders to build a retaining wall on two sides of the new McDonald’s restaurant in Mt Wellington.

One thing that you learn quickly, being from the Waikato, is that place names that start with ‘Mount’ usually have something volcanic about them. This job was no exception.

The retaining wall was going to end at 2-3m high, so the poles needed to be 3 metres in the ground. Logistically, this was going to be difficult to say the least, as the site was previously a commercial yard with many layers of metal and volcanic rock.

The holes were either bored or dug with a digger. The holes for the poles were to be 600mm round and 1.2m apart, and as the holes were prone to cave-ins, every second pole was concreted in before the pole in the middle could be dug. As the ground was metal, cave-ins were an everyday occurrence. If there was water in the hole, a trash pump was used to clear the hole before concrete could be pumped in.

Finally, with all 65 poles in place, it was time to put on the timber. 6m lengths of 150mm x 75mm timber rails are heavy to manoeuvre, often being winched into place. The day the last rail was installed was definitely a welcomed sight.
In the end, the scheduled 18 cubic metres of concrete escalated to 32 cubes, so I can safely say that those poles are not going to fall down. Once the wall was backfilled, and the poles architecturally cut to the finished height, a timber handrail was installed with 40mm vertical pickets.

Written by Todd Sherburd – Fencing Solutions Waikato

Published in WIRED issue 74/September 2024 by Fencing Contractors Association NZ

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