Leakage shall be found out first, mainly in construction joints, expansion joints, post cast strips, external walls and other parts, which will cause leakage if not handled properly. The construction joint shall be treated according to the conventional method before pouring concrete. The surface shall be roughened, the water stop steel plate shall be cleaned, and the concrete shall be watered for wetting. During pouring, the same strength grade of stone mortar shall be used for mortar connection to ensure good contact of the construction joint. To ensure that there is no leakage at the construction joint, an additional waterproof layer must be added when waterproofing the large surface of the basement. When placing the rubber waterstop, ensure that the waterstop is located in the middle of the component thickness, and the centerline of the waterstop coincides with the centerline of the expansion joint. Especially for horizontal expansion joints, when pouring concrete, it must be noted that the concrete cannot directly impact the rubber waterstop to avoid leakage caused by the offset of the waterstop. For the construction of post cast strip, the clearance shall be mainly focused on. For the convenience of cleaning, the cushion at the post cast strip shall be left 100mm lower. In order to prevent mortar leakage, a full-length concrete belt is poured on both sides of the post pouring belt, which has a good control effect on mortar leakage.

The places where the leakage of the exterior wall of the basement is easy to occur include the split bolt, the through reinforcement support (or the hook is too long), and the internal corner between the bottom plate and the exterior wall. For the reasons of key points, it is strictly prohibited to use ordinary screws or through limit support reinforcement for the exterior wall during the concealed acceptance of reinforcement for the bottom plate and exterior wall. All screws and pipes on the exterior wall of the basement must be equipped with three water stop rings. The external wall formwork of the basement shall not be removed too early to avoid loosening of the water stop screw and causing pores during the removal process. In order to avoid leakage at the corner of the bottom plate and the external wall, the quality of the construction of the 300 mm high concrete guide wall shall be strictly controlled. The bottom plate concrete shall be poured to the lower opening of the hanging formwork first, and the guide wall concrete shall be poured when the concrete is about to be re set. When pouring the guide wall concrete, it must be vibrated and compacted. The concrete turned out from the lower opening of the hanging formwork cannot be scraped off immediately. Special attention should be paid to the fact that the concrete at the root of the guide wall cannot be vibrated again at this time, so as to avoid the occurrence of lifting feet and leakage. In order to control the occurrence of honeycombs and cracks on the exterior wall, vibration and curing shall be controlled during concrete construction. Strengthen concrete vibration, implement "quick insertion and slow extraction", and avoid honeycomb caused by missing vibration or excessive vibration. Strengthen the curing of impermeable concrete, assign special personnel to complete it, ensure that the concrete surface is kept wet, and the curing time is not less than 14 days. Finally, during the waterproof construction of the external wall, the water storage test of the external wall of the structure shall be carried out first to ensure that there is no leakage. A waterproof coating shall be added to the wet areas. For the bolt holes, the small wood blocks shall be chiseled out and repaired with 1:2 cement mortar. An additional waterproof layer must be made before the external corners and large surfaces of the construction joints are waterproof.