Stepping up from site manager to project lead for this refurbishment of a three-storey teaching block, Nigel Hayes was proactive and highly professional in delivering a first-class facility. Open and collaborative, he showed excellent leadership and challenged the design, using his experience and leadership skills to find the optimum solution. He moved swiftly to eliminate the water ingress threat created by collapsed land drains and redundant water channels, and mounted a skilful replacement of the precast concrete flooring.
About the Project
Treorchy Comprehensive School, Phase 3B, Rhondda
Refurbishment of three-storey block as music department, completed in 102 weeks.
Client: Rhonda Cynon Taf
Contract: NEC 3 option A
Having joined this four-phase project as site manager on phase 3, Nigel Hayes was asked to step up to the lead role for this phase 3B refurbishment of a three-storey teaching block.
It was something of a baptism of fire. While asbestos had been anticipated, it was much more widespread than expected. With removal of the affected under-slab ducts too expensive to contemplate, Nigel sealed them off by drilling holes and gravity-feeding in a free-flowing grout.
When the internal strip-out revealed problems with the original roof that demanded complete replacement, Nigel changed the design to a mono-pitch falling to the rear of the building. It eliminated the need to install new drainage at the front of the building where existing pipework and cabling heightened the risk of a service clash.
The new roof on and the external cladding fixed, watertight internal progress was the expectation. Sadly, no. Water pooling on the first-floor slab during heavy rainfall turned out not to be from a leak in the roof or wall cladding but ground water finding its way in under the second-floor slab. Trial excavations and core holes revealed redundant service pipes channelling the water to the rear of the retaining wall. Nigel’s effective solution was to grout the pipes and chemically seal the face of the wall.
Perhaps the biggest challenge of all was replacing the building’s precast concrete planks. Given the weight of material and groundwater against the retaining walls, only one floor could be removed and recast at a time to preserve the stability of the structure. Nigel deployed a small remotely operated concrete crusher to break the precast planks free and lift them onto an telehandler for lowering into a skip for removal.
With insufficient space in the site compound to set up a crane of sufficient capacity to install new precast flooring, Nigel decided to cast new floors in situ on metal decking. As the ground floor was occupied by a live electricity substation, the floor above was retained and reinforced with steel beams under the existing planks.