The Sculptures are made with New Zealand native hardwood driftwood.Some of the driftwood may be as old as the Taupo eruption.
They are constructed using galvanized tech roofing screws.
When the sculptures are over a certain size where the weight cannot be safely supported by its legs, a galvanized steel frame is used.
How long the sculptures will last is uncertain but if oiled with the Forestwood deck oil every year and the screws are tightened as required. I would think they will outlast the screws. The screws have a rough life of between 25-50 years depending on the conditions.
The sculptures take different lengths of time to complete. Sometimes things go smoothly sometimes very slowly. The Raurimu Rex took around 6 weeks to complete.