Usually, it is specified that waterproofing system be laid up to 1.5m high on wall, at shower areas. This is to prevent water splashes from penetrating through the wall leading to water leakage problem. On other areas, an upturn of 30cm on wall is common to prevent lateral water leakage out of the wet area.
However, a client recently shared that water penetration through wall can happen even on non-shower area. In one of his projects, a workers’ dormitory, water leaks through the bathrooms without shower. With the high numbers of workers staying there, the bathroom usage is very high and frequent. Even by using only pails during bath, the amount of water being absorbed by the wall is significant. Without getting the time to dry off, the accumulated moist and wetness eventually seeps through the wall.
This is a good lesson to share that an effective waterproofing system must take into consideration of the function, usage and occupants of the building.