First, if the previous use of waterproof membrane, once the leakage can choose to fully redo waterproof. Because the membrane is leaking when it is waterproof, the leakage point is not necessarily in the place where the water seeps. The water may be tens of meters away from the gap. If you simply repair the water seepage without finding a gap, and soon afterwards the rainwater seeps through the gap, the problem of water leakage has not been solved. The gaps in the coils are difficult to find, which is why the coils often have to be repaired once leakage is found.
Second, if there is no waterproof before, once leakage occurs, it should be fully waterproof. No water was leaked before without leaking because the building was still dense. After a certain number of years, a certain amount of settlement will occur under the gravity of the earth. With the sun and rain, many small cracks will be produced. It is not surprising that water leakage is not present at the beginning. At this time, only waterproofing the leaking point can only be an expedient measure and cannot fundamentally solve the problem.
Third, if waterproofing is done with waterproof paint, such as a cement-based K11 waterproof paste (coating), then leaks occur in individual areas, and then only a single repair is needed. K11 waterproof coating has penetrated into the building base layer, closely combined with the substrate, and closed the pores, which plays a role in reinforcing the building. At the same time also has a certain degree of flexibility, can resist a certain vibration displacement. These features can protect their individual areas from being damaged and need to be repaired separately.
Summary: Everyone found leaks in their homes, or it depends on the specific situation to do waterproofing.