Sewers

Can the slope to the main sewer line change from a negative slope to a positive one?

Our guest toilet clogged. Plumber tried to snake it, pushed something through and then diagnosed it as poor jets. Next day our kitchen sink clogged. Plumber snaked it and got it flowing slowly. 4 days later our master bath sink backed into the shower. Today plumber checked the main drain through the cleanout and couldnt clear it with a 300lb snake. Stated he couldn't push through and then got a camera out. He saw a massive toilet paper clog and noticed water collecting in the main, down stream from the clog. He diagnosed it as improper installation or a shift of earth around the main, not adhering to 1/4 inch slope every foot. He stated that he could not remove the clog and to fix the problem he would have to dig out our main pipe in our crawl space and re-lay 50 feet of pipe. Damage estimate is $4000. The house is 30 years old and we bought it 5 months ago. Can earth move sufficient enough to change the slope of the main with sudden effects? Why can't he remove the clog?

Public Comments

1. I would guess that a joint in the main line broke and the water from it washed out the dirt from under it. Any waste now going through the line meets a point where the pipe is lower from both directions forming a valley for the waste to sit in and form a clog.
2. in the 3 years I worked on a crew that installed sewer and storm drain lines, from 4 inch to 60 inch pipe, we never once laid a positive grade for anything.....and i would have to suspect that any "natural" earth movement that would shift a pipe to that degree would be something akin to an earthquake that would not only be felt but would break the line in more than one place and at more than one location. sounds like you need a second opinion on this one. at the very least the should be no reason why the clog can't be removed....there are many methods available for removing clogs in the line beyond just a snake and if he knows what he's doing he should be able to at least clear the line. get someone else to look at it and if their determination is the same, then something strange is going on in the subgrade below your house. i will add that, depending on the company that did the subgrade work and site prep for your house.....i have seen some very shoddy site prep in my day and if they had unreasonable deadlines or weather to deal with, then thye may have skimped on site prep on your lot and you may have experienced some settling after the fact if they didn't get the required compaction in the soil....but that would also implicate the city inspectors as having signed off on site prep they knew was substandard. some settling of the pad your house is on and the subgrade is expected, but nothing on the order of changing a negative grade to positive.....get a second opinoin and you may find that someone more competent can fix your problem....or you have bigger problems if it is indeed a poor site prep and subsiding subgrade.....the only other possiblity is that there was a break in the line and it washed the dirt out from under the pipe and due to subsidence there has developed a kink in the line, but that is less likely that poor site prep
3. well that doesnt happen. it could be backgrading yes. I have seen it a lot. what i think really has happend is you have a broken pipe that needs to be replaced. did you watch the tape with him. watch the tape and look for roots in the line
4. simply poor installation 30 years ago. you are better off spending the money on getting the job done properly NOW rather than continually pay to get your lines unblocked and THEN spending the money. get a second opinion first. it doesnt matter on the weight of the snake btw it matters on the length of the rods. get a second opinion with a company who has a camera also, you might just have one section of drain thats collapsed or maybe have tree roots growing into the drain. get a quote from both and go with the cheapest!
5. It may not be the sewer line at all. It could be low flush, 1.6 gallon commodes. I have seen many times when the 1.6 gallons of water was not enough water to carry solids and waste any distance, so, as a result, you have solids and paper building up in the line because of a lack of water to carry it on through. Before you start replacing anything, get the line unclogged and then camera the line, it may not be broken. Also, check your commodes to see if they are the low consumption commodes. Those are the most economical and least invasive places to start. Best of luck.