The reasons for the indoor putty falling off on a large area and the walls are wet are nothing more than two reasons:

1. Exterior wall tiles fall off large areas and long-term rain lead to water leakage.

Some exterior wall tiles on site are well organized and preserved, but there are only a few that fall off slightly. When it rains, the rain water hits the tiles and is affected by gravity and flows away quickly. Except for the heavy rain that lasts for more than ten days, a small amount of rainwater may enter the room. However, the putty powder in your indoor room falls off on a large scale, so it can be ruled out that it is the reason for the exterior wall.

2. The original waterproof layer of the roof daughter wall is damaged, and water accumulates in the structural layer for a long time, which penetrates into the room and leads to water leakage.

The building has a long service life and is affected by geological settlement (it can be seen from whether there are irregular cracks in the room). The waterproof rolls in waterproof parts such as the original daughter wall and expansion joints of the roof are affected by stretching and deformation, which causes water accumulation in the structural layer to lose the barrier of the waterproof layer. Through the joint between the daughter wall and the floor layer, it penetrates from top to bottom to the lower red brick structure (as shown in the figure below). The red bricks are sparse and porous, absorb water into the room, causing the inner wall to be damp for a long time and the putty layer to fall off.