379 Brougham St, Sydenham, Christchurch

Date: June- August 2016

Client: Jarris Holding Ltd

Structural Engineer: Lewis & Barrow Ltd

Contractor: Kinstruction Ltd

PT Subcontractor: BBR Contech

As a result of the Canterbury earthquakes, this commercial property showed evidence of differential settlement of the warehouse floor slab. During a major refurbishment of the property, Jarris Holding Ltd decided to lay a new post tensioned slab over the existing slab. They had prior experience of this, as BBR Contech had already completed an overlaid post tensioned slab on one of their other buildings on Coleridge Street.

A layer of hardfill was laid and compacted over the existing warehouse area to re-level the floor, with a new 150mm post-tensioned slab poured on the top. To post tension the slab, holes were cored in the existing concrete panels and the new panels had pockets cast in. This allowed the slab to be poured in one pour, without any infill strips, leaving a beautifully smooth and joint-free slab over the full 2,516m² area.