Murney House

Award:  Other Entrants

Project:  Murney House

Entrant:  Waddell Construction (Ashburton) Ltd

Owner:  F G & K G Murney

Architect:  Noordanus Architects Ltd

Consultant:  Lewis & Barrow Ltd

Contractor:  Waddell Construction (Ashburton) Ltd

Other Firms:  Allied Concrete Ltd; Fenwick Reinforcing Ltd

A suspended helical stair, cast in-situ, in the entrance of this new home proved to be a rewarding and challenging task.  Precasting the stair off site was not an option in this situation as the stair is counter balanced by a 6m x 1.2m x 0.6m beam below the floor and could only be connected by being cast over the 24mm connecting reinforcing anchor rods protruding from the floor.

Under floor heating pipes restricted any temporary fixings to the floor for framework therefore plywood was positioned on the floor with a strategically positioned cut out to suit the stair to floor connection.  The outside walls were studded to suit the radius of the internal curve and the exterior curve, the centres of these were different as the stair also tapers as it ascends.  The formwork for the underside of the stairs proved the biggest challenge, I likened it to building a boat, as there is not a straight line in it.  Most reinforcing was hand bent on site (150 centres both ways, two layers).  Riser formwork was individually cut to suit each step, these were set up to a radial with a different centre point to the two stringer centre points.  Eight ton of concrete later, placed carefully and trowelled to a finish ready to take the marble cladding.

In 25 years of building, this was one of the most rewarding concrete casting jobs I have done, and it will be the focal point of the entrance of this 1100 square metre home of distinction.