Waterproofing for Waste Water tank

Waste Water Tank Waterproofing

Scope: Waterproofing of waste water tank and reservoir by lining.


  • Heavy duty coating for steel and concrete
  • Abrasion and impact resistant
  • Excellent resistance to water and chemicals
  • Can be exposed to water immediately after application

1. For New Concrete structure:

  • The use of Superplasticizer range, will help to achieve overall better concrete performance and watertighness.
  • The addition of Silica Fume at the dosage rate of 5-10% by weight of cement in concrete mixture will improve mechanical and chemical resistance and therefore durability of the concrete structure in an aggressive environment.

2. Solution for Construction joint:

  • Waterstop (Waterbar V) are flexible PVC internal and surface waterstop specifically designed to seal construction joints.
  • Surface preparation of concrete substrate in construction joint area is essential before pouring the following concrete section.
  • Surface retarder admixture can be used to give a proper mechanical key for concrete substrate in construction joint.

3. Solution for movement or expansion joint:

  • Waterstop (Waterbar O) is PVC flexible internal or surface waterbars.

4. Solution for pipe penetration:

  • Sika Sika Hydrotite CJ type is particularly suitable and easy to use to seal protrusion or pipe/conduct through new concrete structure.

5. Repairing concrete substrate before any lining: (if required)

  • Any patching or repairs to the structural concrete should be carried out by using bonding bridge and repair mortar.

6. Substrate surfacing prior to lining application:

  • Sikagard 75 Epocem can be used when the concrete surface is not smooth enough, getting holes, cavities and other surface defects.
  • In this case Sikagard 75 Epocem can be applied in one coat only, at a rate between 1.2 – 2 kg/m2 depending on surface quality.
  • Prior to Sikagard 75 Epocem coating application, the substrate shall be prepared properly in order to remove any grease, oil, chemicals, loose adhering particles, dust.

The concrete substrate shall be wetted down as well. Mixing of Sikagard 75 Epocem shall be conducted as follows:

  • Pour component A (white liquid) into component B and shake vigorously for 30 seconds. Pour the binder mixture (A+B) into a 30 liters pail and add slowly the component C.
  • Mix for 2 minutes, using a low speed electric stirrer (max. 500rpm) equipped with a spiral mixing paddle.
  • Apply Sikagard 75 Epocem first coat with notched trowel at the consumption rate of approx. 2 kg/m2. Let it cure for 2 hours
  • Apply the second coat of Sikagard 75 Epocem with a trowel at the consumption rate of approx. 1.5 to 2 kg/m2.

In case of application of Sikagard 75 Epocem as a moisture barrier, a minimum thickness of 2 mm  is required and application shall be conducted in 2 layers.

7. Chemical Resitance lining Sika product:
On the prepared dry or damp concrete surface or on the 24 hours cured Sikagard 75
Epocem, the application of Sika Poxitar F, high chemical and mechanical resistance
epoxy resin, can be carried out as follows:

  • Mix the 2 component of SikaPoxitar F with a low speed mixer.
  • Apply Sika Poxitar F by roller at the rate of approximately 0.5 kg/m² per coat. 3 coats are generally required. Sika Poxitar F can also be applied with airless spraying equipment.