Basement tanking is a term referred to in the construction industry that refers to different systems that help keep a basement, or even an underground structure, free from water. There are two basic systems that are referred to as tanking systems that are used today. External systems are the most common option used when the basement or structure is being built, and internal systems are used after the building has already been formed. Basement tanking is an industry term that basically means a waterproofing system designed to prevent water from gaining entrance into a basement or underground structure.
External basement tanking systems are most commonly installed when the basement or structure is made. The main concept of them is to keep water away from the junctions where the walls and the floor meet, since this is a weak spot formed by a joint. There are various designs when it comes to making an external tank, but most of them use a waterproof membrane that is basically wrapped around the concrete. It is installed before the cement is poured, and after the forms have been removed it is basically wrapped around the entire concrete section, effectively enclosing it inside of a tank. The outer edges are protected from constant water by installing drainage pipes and surrounding the area with gravel, which helps carry the water away from the cement and the membrane, rather than allowing the water to constantly beat against them.
Internal basement tanking systems are very similar to external ones, except for the obvious fact that they are inside the basement or structure, rather than built in along the outer edges. Once again, various different designs are available that require varying degrees of interior preparation. Some tanking designs require that a coating be sprayed onto the inner walls and floors, while others are applied with brushes or rollers. Either way, some type of drainage field is required along the outer edges that funnel any water into a hole in one of the corners where a sump pump is installed. The sump pump ejects the water through a pipe out of the basement or underground structure into the surrounding landscape, effectively keeping water from forming inside of the basement.
Basement tanking systems are designed to keep water out of basements and underground structures, and they are commonly referred to as water management systems. External and internal systems are designed to work in the same efficient manner, but since the majority of problems associated with water in basements occur after the structures have been built, it is becoming a common practice to remodel existing basements and to include some form of internal drainage system. The major downfall to basement tanking systems is that once the majority of them are installed, it is extremely hard to remove. In areas where permanent systems are not allowed, these water management systems will have to be substituted for ones that are not so permanent.
