First, flexible waterproof casing waterproof layer of material caused by improper use. Waterproof layer material selected indicators include mainly the lack of construction thickness; improper process; two or more waterproof composite materials used improperly influence each other their respective water effects.

Second, flexible waterproof layer is cut in the role of groundwater crack to form an integrated flexible waterproof layer waterproof layer destruction of water penetration. Aluminum profile of each floor basement waterproofing layer can easily be cut to crack, basement floor is usually 1-2 weeks Yang moldings along the road, where the structural concrete are sharp, but also at the second waterproof material construction, the sun angle line waterproof relatively poor, in the process of settlement construction, the site can easily be cut to crack. Another basement floor flexible waterproof outer layer and are based on anti-paste method of construction, and the method of construction can not be done with the structural layer waterproof layer bonded tightly when floor deformation and easy to make flexible waterproof layer and bottom disengaged, disconnected structure waterproof layer and easy drum break in the action of groundwater.

Third, flexible waterproof casing waterproof layer of concrete defects in accordance with the perforation damage. This is due to a large sink uneven structure led to the destruction of cracking flexible waterproof layer; secondly when the outer anti-paste method of construction of the concrete floor has a larger outer hollow, when people do not know can not repair concrete. Produce waterproof layer attached to the back of losses in the water under pressure, small local waterproof layer breakdown.

Fourth, the outer facade anti-corruption law posted outside flexible waterproof casing waterproof protective layer of local damage or deformation plays a waterproof layer. Basement walls are usually flexible waterproof layer were adopted after the formation of the outer structural concrete outer anti-paste method of construction, it has the advantage of flexible waterproof layer can be well combined with structural concrete, but the majority of the current practice of only the outer waterproof layer do brick layer of protection when larger basement sink or backfill construction, it is possible to make a waterproof outer layer of brick protection layer fracture deformation or vibration partial destruction of the waterproof layer.