Waterproofing - Best Practices

Sunny Surlaker, MC-Bauchemie India Private Limited, Mumbai

In today's harsher/polluted environment, and due to extreme requirements we put on speed, economy and construction practices, the durability of concrete is severely affected. Due to construction and/or material problems, structures both above and below ground are susceptible to waterproofing problems. Dampness entering the living space (especially through ceilings) is an indication that the structure has failed and that structural elements have already begun deteriorating.

Waterproofing is important in protecting the structure and ensuring that the structure is usable over its service life. The forces exerted by water are enormous and its effects are unpredictable. Water enters the structure through the weakest route. Some typical problems are shown in Figure 1. A reliable waterproofing system installed by professionals is essential to achieve lasting protection from water damage. Much is demanded here from both the material and its applicators.

In many projects, damp proofing is expected of the underground waterproofing system. The ACI Committee 515 report explains the difference between the two: Waterproofing is treatment to a structure to prevent the passage of water under hydrostatic pressure while damp proofing is a treatment to a structure to resist the passage of water in the absence of hydrostatic pressure. While designing the waterproofing system, actual service conditions should be considered for selection of the material.

The most important aspect for any waterproofing treatment is its performance. Materials and systems should be tested for capillary absorption as well as penetration under hydrostatic pressure. Such tests are available internationally and materials can be tested anywhere in the world to adhere to ASTM/EN standards. In India, IS 3085 can be used to test water penetration under pressure.