Plumbing Africa November 2019 | Page 49

PROJECT 47 contractors, but as soon as they start with the building structure, we have to move to another for safety reasons. They have a block of, say, five days to complete a structure, whereafter we can move in.” The wet services design was done by Mike Gough of MG Consulting, who provided the sanitary schedules and design drawings for Industrial Plumbers to follow. Being geologically a dolomitic region, a concrete raft of criss-crossing reinforced trenches provides the foundation to give stability and the plumbing has to be positioned beneath this raft rather than within it for the reason that it shifts, and anything within it would compromise the foundation. The main water and sewer lines were installed from the water meters by the groundwork engineers, BSM Baker, to each block, from where Industrial Plumbers takes over. From there the pipes are routed via ducts, while the pressure regulator valve (PVR) and fire water discharges are positioned just before the latter goes into the hose reels while the water supply is reticulated throughout the building to each unit. Beneath the sink and out of sight. “We install all the baths, sinks and toilets up to and including the point of the shower rose, in addition to the connections to the water supply. We chose our own suppliers, except for the hot water system, which is EMS. We do everything from the water meter to the tap spout,” says Du Toit. The cross-over point from plumbing construction to plumbing maintenance is a sensitive issue, he says. A clean plumbing system is handed over, but other construction trades often don’t pay sufficient attention to the plumbing, meaning that rubble and soil can end up in the main line and bite you a few months down the line. “The same happens when other contractors later, for instance, put nails through our pipes and it is not immediately evident. Later, when the water is switched on and trickles down the wall it appears to be a construction plumbing defect. At that stage, we need to knock holes in finished walls and ceiling, resulting in a lot of patching. This in turn can result in entire walls having to be repainted to cover the patches. “All the piping we use here is Geberit Mepla, a multilayer crimped pipe, which in my opinion cannot be beaten by any other pipe. The well-known problem with copper is that it gets stolen and you are not reimbursed for it – it can be repeatedly stolen. Aesthetics trumps everything else at Serengeti, with all plumbing invisible behind closed doors. “Everything above ground is PVC and everything below ground HDPE,” says Du Toit. Challenges of the job “Luckily,” says Du Toit, “any lesson to be learned we had already learned as we paid our school fees during Phase 1. Phase 2 is exactly the same layout with only some of the finishes such as tiles being different. The lessons from Phase 1 related to the sequence of work, which was specified in the schedule of works but required some considerable modification during the actual work. For instance, according to the programme, the shower bath is installed and then the tiler has to tile the shower bath from the top to bottom. We found it is preferable for the tiling to be done first, stopping just above the area of the bath, we install the bath and the tiling is only then completed. Otherwise, the tiler stands on the bath to tile, damaging it and sometimes requiring a new bath.” These sequence-of-work issues were resolved with the main contractor, though it would nonetheless put the November 2019 Volume 25 I Number 9 Industrial Plumbers asked for the installation sequencing to be changed, in order to minimise damage to the baths while tiling was being done.contractors in the rush to complete on time. www.plumbingafrica.co.za