Although there are numerous systems available for tanking and structural waterproofing, they mostly fall into two categories - cement based and plastic membrane based. These systems are equally appropriate for new-build or refurbishment work.
The term 'tanking' refers to a waterproofing system that includes the floor and all walls within a treatment area. The term structural waterproofing is used when specific areas are treated, such as individual walls but not all areas. For example, the floor might not be included in the treatment or perhaps all the walls are not below ground.
Cementitious systems
Cement based systems are typically incorporated into the plastering system. Sika rendering is an
integrated plastering and waterproofing system. Other cement systems such as Vandex are special
dense render coats incorporated into the plastering system by trowel or spray application.
Vandex application
Cement based systems work by sealing the structure to prevent damp and water penetration to the internal wall surfaces. Vandex can be applied internally or externally.
Plastic Membrane application
Plastic membrane systems
Cavity drain plastic membrane waterproofing systems are often referred to as water management
systems rather than tanking or structural waterproofing systems because they work not by sealing
structures but by effectively dealing with any water penetration that occurs.
One of the problems associated with cement based systems is that sealing a structure results in a build-up of hydrostatic water pressure in the wall and floor structures behind the waterproofing system. It is therefore vital the wall and floor structures are capable of withstanding this pressure otherwise systems failure will occur.
Plastic membrane systems effectively line the structure. In a full waterproofing system this would include the walls and floor. Within this lining is generally a series of special drainage channels and possibly a sump and pump arrangement to remove water from the system.
Plastic membrane systems offer a number of advantages over cement-based systems. A membrane system will generally have walls constructed independent of the waterproofing system. This means fixing to the walls is possible without the risk of puncturing the waterproof barrier. The cavity between the walls and membrane system can also be insulated and used for pipe and cable runs.
