Recently, a damp spot has started to appear on the wall in the basement. At first, I thought it was just condensation, but the stain is growing, and now it smells musty. Maybe there is a leak in the drainage system or back pressure in the sewer? I don't know how to check without special equipment. Maybe someone has had a similar situation — where to start so that it doesn't turn into a flood?
I also noticed that during heavy rain, this moisture increases, and there is a slight hissing sound near the wall, as if something is seeping under pressure. I'm very worried that the water will start to destroy the foundation or mold will appear, because we store things in the basement. Maybe it's worth digging a drain outside or checking the pipes with a camera, if possible? I want to avoid large expenses, but I also don't want to miss the moment.
It's funny that it started with a small damp spot for me too, and ended up with the basement almost flooded. It turned out that the cause was an old drainage pipe that had cracked under the foundation. It is impossible to find the damage yourself — you need equipment for video inspection. So I contacted plumber mississauga and they really solved the problem quickly and without unnecessary destruction. They came with a camera, found the crack, replaced part of the pipe, and installed a safety valve. It's been six months now — the basement is dry, the smell is gone, and I can sleep peacefully, even during heavy rains.