WP600 Waterproofing – Potable Water Tank


  1. All surfaces to be waterproofed must be firm, clean, dry, sound and smooth. All grease, oil, wax, curing compounds, loose material, paint and any other contaminants must be removed, masonry surfaces must be pointed flush and surface defects repaired. New concrete must be cured for a minimum of 28 days.
  2. External corners to be waterproofed must be bevelled to ensure a smooth transition of membrane from vertical to horizontal surfaces.


  1. If the area to be waterproofed is subject to continuous water seepage, seal off the flow using Mapei Lamposilex Waterstop, then continue as described below.

    Mapei Lamposilex Waterstop is an ultra-fast setting and curing hydraulic binder for stopping water leaks. When mixed with water, Lamposilex produces a paste with a plastic-thixotropic consistency easy to apply even on vertical surfaces, with no need for formwork.

  2. Repair all surface defects with Aftek Penapatch Structural HB80.

    Aftek Penapatch Structural HB80 is a high strength; high build shrinkage compensated structural repair mortar.

  3. Install a Gunnable Waterstop around all penetrations. The waterstop must be packed in between at least a 50mm cover of Aftek Penapatch Structural HB80. Gunnable Waterstop products are caulk-grade, single-component swelling pastes used to stop water infiltration through concrete construction joints.
  4. Apply WPA 160 primer to all non-porous surfaces such as PVC pipe penetrations.

    WPA 160 is a specialised solvent-free primer designed for enhancing the adhesion of subsequent membranes, adhesives, toppings and decorative finishes over non-porous substrates.

  5. Apply WPA 100 membrane in a minimum of two coats to achieve the required dry film thickness. Ensure that the previous coat has completely dried before applying the subsequent coat(s). NOTE: All penetrations must be waterproofed.

    WPA 100 is a single-component, fibre-reinforced, rapid-drying, cementitious waterproofing membrane.

  6. All transitions must be detailed utilising WPA Elastoband.

    WPA Elastoband is an innovative detailing system designed for waterproofing and sealing all types of joints, junctions and transitions subjected to movement.

IMPORTANT: Allow membrane to cure for 10 days with fan-forced ventilation.

Products Used

  • Mapei Lamposilex Waterstop
  • Aftek Penapatch Structural HB80
  • WPA 160
  • WPA 100
  • WPA Elastoband