About 4 years ago, my bathtub had a really bad clog. Whenever I used the washing machine, it backed up into the bathtub but never drained. I called 3 plumbers, and not any of them could unclog it. Then suddenly one day it was unclogged. But for about a week whenever I used the washing machine, it still backed up into the tub, but for that week, each time it backed up, about half a pound of small pebble like rock came up with it. There's no way that could have been a clog, so I have to believe that a pipe had probably burst. But since the tub was draining good, and after that first week, I was able to use the washing machine without it backing up into the tub anymore, I never did anything about it. Now with all these sinkholes happening, it got me thinking... All of that water in the tub each time I took a shower had to have been draining somewhere, correct? 4 years has past. Could I sort of believe that I have a good sized sinkhole under my house?

Your sewer problems are just like everybody else's across the country. I don't think they indicated "sink holes" under you house. I suggest you have sewer video inspection done and that will tell you exactly what the culprit is. Back to you. Milo

Your sewer problems are just like everybody else's across the country. I don't think they indicated "sink holes" under you house. I suggest you have sewer video inspection done and that will tell you exactly what the culprit is. Back to you. Milo

I know what you are saying, but not everyone has a half a pound of rock backing up into their bathtub each time the washing machine was being used. And then suddenly the bathtub was all unclogged and draining excellent. In total, I would estimate, that at least a good 3 pounds of rock had backed up into the tub during that last week it was clogged. Doesn't it mean either of two things? Either when I took showers that last week, 3 pounds of small rocks and sand was rinse off me, or that a pipe burst under the tub. I get dirty sometimes, but not that much. All I'm really asking is hypothetically, what if a pipe did burst under the tub where it drains, after 4 years of the water draining into the ground, is there a good chance that a sinkhole could be there? Or does it take long for that to happen.

P.S. I should have mentioned this the first time, but a friend of mine came out with one of those cameras, and he put it down some outlet in the front of my house and was able to go back 28 ft until he hit roots. But he couldn't go any further with the camera because the roots prevented him. So there still wasn't a positive answer of if there was a break or not.

28 ft back by the way is right where my bathtub begins. He wasn't able to see any water on the monitor when I turned on the bathtub full power.

I guess the only way to be sure is to pull up the bathtub? I was just tryng to prepare for what could be under it when I do. Thank you. I appreciate you trynig to help me with this.

You won't accomplish anything by pulling out the tub. Sewer Video Inspection should be conclusive and the best way to go. If your plumber accoutered roots, and could not proceed any further with the camera, he should have snaked your sewer to allow further access with the camera. Rocks in the pipe may indicate your sewer pipe is broken and surrounding gravel is entering the pipe. Volume of discharged water from Washing Machine pushes all debris backwards. Since your tub drain is 3' lower than w/m drain, sewer back flow will first show in the tub. I hope it all makes sense to you. It is hard to explain unless you understand how is sewer system installed and how it works. But in any case, I would not worry about sink hole. Milo

I have a hard time seeing a 1/2# of rocks backing up. Water flows down and gravity pulls rocks down. With a higher specific gravity they don't float. Where do you live and are sinkholes prevalent in your area?

Once the plumber hit roots he should have backed iout the camera and gone in with a cutter. You sure have a breech but maybe not a broken pipe.