Floating Cover Fabrication & Installation Across Africa

Defined Sump Cover Design

Most of our floating covers are defined sump covers. Rows of floats and sand-filled ballast tubes, sealed inside the cover membrane, pull the cover taut and form drainage channels (sumps) across its surface. Tension takes up the spare material as the water level rises and falls, so the cover stays tight, is safe to walk on, is easier to keep clean and is far more secure in high wind.

• Scrim-reinforced cover membrane, with floats and ballast tubes encapsulated in geomembrane for long exposed life
• Sumps laid out to suit the reservoir: profile trace, double Y or X pattern
• Short floats and ballast tubes (about 0.91 m) on the side slopes so the cover articulates and follows the slope as the level changes
• Long floats (about 2.75 m) and ballast tubes (about 1.83 m) over the flat floor, where the cover only needs to follow a level surface

How Rainwater Leaves the Cover

1. 01

   Collect

   Rain runs off the taut cover, drains through the gaps between the segmented floats and collects in the sumps, away from the stored water.

2. 02

   Pump

   Scavenging pumps sit in the sumps at the sump intersections, held in a buoyant membrane-encapsulated foam collar so they follow the water level.

3. 03

   Discharge

   When the pump switches on it empties the sump through a discharge hose that runs, with the power cable, along the sump and off the cover.

4. 04

   Vent

   Floating vents, a floating base under the membrane with a boot and vent riser fitted from above, release air and gas from under the cover.

What We Fabricate

We shop-weld cover panels in our own facility before mobilisation:

• Cover panels in FC45 or FC60 rLLDPE, CSPE, rFPP or the specified membrane, rolled and numbered to the as-built layout
• Float and ballast sleeves that form the defined sumps and guide rainwater to the pumps
• Encapsulated floats and sand-filled ballast tubes, pump and vent bases, hatches and inspection ports
• Pipe boots and penetration seals made to each pipe

How We Install

1. 01

   Site survey

   We survey the reservoir geometry, operating levels, anchorage and access.

2. 02

   Deployment

   We deploy panels to the layout and complete field welds.

3. 03

   Anchorage

   We install perimeter anchorage that holds the cover through the full water-level range.

4. 04

   Rainwater system

   We install and commission the sumps and drainage pumps.

Our Seam Testing

1. 01

   Trial welds

   Every welder and machine runs a trial weld at the start of each shift and at every change of operator or conditions, and we peel-test it before production welding starts.

2. 02

   Non-destructive testing

   We air-pressure test every double-track fusion seam and vacuum-box test every extrusion weld along its full length.

3. 03

   Destructive testing

   We cut seam samples at the frequency set in our QA/QC plan and test them in peel and shear, on site or through SANAS-accredited laboratories in South Africa.

4. 04

   Repairs and retests

   We mark, repair and retest every defect, and record each repair against the panel layout.

Technical Resources & Project Submittals

Download our published resources, or ask us for the current material data, fabrication details, installation method and QA/QC plan for your project.