Hydraulic ram pumps and Sling Pumps

Make an opening in the shutter ply at the manhole, as all the inside timber has to be removedthrough it later. The opening should be 650 x 650 mm.Fill all gaps in the shutter or between shutter and wall with paper or plastic.Lay a damp proof course on top of the tank wall.Cut hardboard into strips 300 mm wide, or use hardboard from the slab.Tie the hardboard around the top of the tank to form an edge shutter so that this edge is 100 mmabove the wall.Form an edge shutter for the manhole. This should be 75 mm deep and slightly larger than the holein the shutter (650 x 650 mm) so that it can rest on the shutter.Paint the shutter with shutter oil or old engine oil.5.2.13 Roof reinforcementOn the preparation area cut a piece of reinforcement mesh to the size of the circle. If this is notavailable use 6-mm reinforcement mild steel and tie together in the same way as the floorreinforcement.Place the reinforcement in the shutter and either support it with 20-mm plywood blocks or distributeabout four wheelbarrows of concrete in the shutter and place the reinforcement on top of thisconcrete. Ensure that the reinforcement is 20 mm above shutter level.Double the reinforcement in the centre above the pier which will support the roof.5.2.14 Concreting roof slabThe concrete used must be of good quality and care should be taken in selecting the sand andstone. See Chapter 3.Start at the side furthest from the manhole and work evenly towards the manhole opening.Use a straight piece of timber, the edge shuttering and manhole shutter as guides to form a smoothsurface as the concrete is laid (Fig 5.37)54figure 5.37