What is the cause of water seepage in the wall?

What is the cause of water seepage in the wall? 1. No insulation layer. In the past, many residential walls had no insulation layer. In winter, the temperature difference between indoor and outdoor is large, so it is cold outside the wall and hot inside. Because of the high temperature inside the wall, condensed water will form on the wall, which will lead to the wall being wet, and it is the whole wall. This kind of situation usually only appears in winter, but it will be fine in summer. But the sequela is that it will leave many ugly mildew spots, which will affect the beauty of the wall. 2. The water pipe in the wall leaks, and the water pipe embedded in the wall leaks, causing the wall to be wet. This usually happens near the bathroom, or on the top of the house, or on the wall. Generally, there is leakage at the joint of embedded water pipes, including whether there is water pipe leakage in the wall at home and upstairs, and water seeps into the partition wall. 3. Poor waterproof measures ① The waterproof project of the upstairs ground is not good, and the wall leakage caused by the poor waterproof of the bathroom next door or the bathroom next door upstairs. Once there is water in the bathroom, it will slowly seep down.

(2) The joint between the upstairs water pipe and the ground is not waterproof, and there is a possibility of water seepage near the pipe. Water flows down the water pipe, leading to water seepage on the roof. 4. Inappropriate painting works. When painting the wall, the first time the wall paint is not dry, it begins to be painted again, and the water vapor in the wall fails to evaporate, resulting in the wet wall. 5. The masonry mortar of masonry is not full, and the mortar joint is empty, which makes the capillary channel form siphon effect: the material of indoor decorative surface is loose, which is easy to distribute water in capillary; Uneven plastering thickness of exterior wall facing leads to uneven water collection speed, and plastering is prone to cracks and shelling, and the bottom ash of frame is not dense and there are sand holes, which causes wall seepage. 6. The joint between doors and windows and the wall is not tightly sealed, the window ceiling is not equipped with an eagle mouth and a drip line, and the outdoor windowsill is higher than the indoor windowsill. There is no slope along the river on the outdoor window sill, which leads to the phenomenon of water pouring. 7. There is no serious blockage and sealing paste between the window frame and the wall, or the protective tape of the window frame is not torn off, resulting in water seepage. 8. Inappropriately block feet, hands, eyes and other holes.