Could you tell me if the water in my house sometimes drains slower than usual and there's a damp patch near the yard? Could this indicate a leak in the sewer line? I don't want to start a fire, but I don't know how serious this is.

This could very well be a sign. At first, my drains were simply "slowed down," and then moisture started seeping through to the lawn. It turned out the line had partially collapsed inside, and the water was simply seeping into the ground.

Sometimes small signs turn out to be clues we don't even notice until the situation gets out of control. When I first noticed damp spots in my yard, I also thought it was just the rain. But later it became clear: the source was an underground sewer line that had begun to deteriorate. To avoid guesswork, I found specialists who offer comprehensive diagnostics and repairs https://bens.plumbing/services/sewer-li ... r-seattle/ . They used a camera, went along the entire length of the pipe, and found a section with a subsidence and partial blockage. After the repair, the wastewater flow completely stabilized, and the damp areas dried out. It's best to address such problems immediately—damaged sewer lines can lead to basement flooding and foundation damage.