How to judge whether the old wall needs to be waterproofed?

Update time:2022-10-25

Testing with a professional moisture tester can scientifically judge whether the wall needs to be waterproofed. According to Crifford's long-term experience in renovating old walls, the moisture content of the wall should be lower than 7% when the wallpaper is refurbished, and the moisture content of the wall when the interior wall or exterior wall paint is refurbished should be lower than 10%. If it exceeds this standard, it should be done Special waterproof treatment.