If you are having problems with your sewer line or your septic tank you may have to call a plumber to figure out what could be wrong with your drain lines. There are many tools that the plumber can use to find out what is wrong with the sewer line including drain cleaning machines, sewer inspection camera’s and something called a pipe bursting machine.
The pipe bursting machine is one of the best options for the replacement of an existing sewer line and this process that plumbers using this machine is called pipe bursting. A licensed plumbing contractor can use this method to excavate and expose the old pipe which is connected to the septic tank or the city sewer system.
The starting point would typically be in the street where the plumber would locate the sewer lateral (the sewer line from the house to the city sewer line in the street) that connects to the city sewer or your septic tank like we mentioned above.
The other hole would be either just outside the foundation where the line exits the house, or, in the basement just before the line exits the house. A strong steel wire rope cable is pulled through the sewer lateral between those two points. A cone shaped bursting head is attached to the cable along with the new polyethylene pipe which is attached behind the cone shaped bursting head. At the other end a hydraulic puller is placed which takes hold of the cable and pulls it with great force in a series of short strokes. Typically speeds are in the area of 10 – 15′ per hour. The cone shaped bursting head goes through the old sewer line expanding it over the cone until the old pipe bursts creating room for the new High Density Polyethylene Pipe (HDPE) to be pulled through the ground where the old pipe was. Lengths of the HDPE pipe are joined together using a plastic welding process that creates a new seamless one piece sewer line with no joints that can leak or, be penetrated by roots. Once the line is pulled through between the two holes the connection to the house and the city sewer is reestablished and the line has been replaced.
There are some limitations to using the pipe bursting process:
The first is the line has to be in good enough condition for the cable to be pulled through the line.
Pipe Bursting will not fix a sag, or, belly. The bursting head and new pipe follows the path of the old pipe.
Rocks, ledge and some other conditions may jam the bursting head preventing it from passing and still require excavation to complete the job.
Some bend configurations may not allow pipe bursting as the bursting head may exit the pipe and get stuck requiring excavation.
I had my sewer line replaced by pipe bursting at my house. I have a steep terraced front yard with several retaining walls. They couldn’t have gotten an excavator into most of the yard and redoing all those walls would have cost a bundle. Pipe bursting saved my day.
That sounds like it would have been a very expensive excavation.
We don’t have anyone locally who does this in my area. I know the job I did yesterday though, that guy needs something! His plumbing issues just got worse.
Most of the time larger companies are the ones that will be doing this type of work.
Were there conditions present on the job that would prevent excavation from being viable?
Hi,
I’ve been having roots in my sewer line for a couple years now, and my city was nice enough to clean out the line for a very minimal fee. They just came by today and when they tried to put the 3 inch cutter down the line, it got stuck. They said there is probably an offset in the pipe, which if they can’t get a 3 inch cutter through is serious. It’s supposed to be a 5 inch line, so it sounds like almost half the pipe is shifted. I’m going to get them to send a camera through and get a better idea of the situation, but it sounds like I’m going to have to replace the pipe, and might as well replace all the line up to the city connection, 35 feet from the end of my house. That way I’ll take care of the root problem too. Now my question is if the pipe bursting method is a good option? I’m assuming they can access the line from the sewer main for one entrance, which seems to be what a lot of web sites say. As for the other end, I have a pit in my basement floor at the wall of my house. There is a Y connection off the main line that is how the city has been cleaning the line. The pit is maybe 1 and a half feet wide and a little over 2 feet long. The city people have to use two foot rods to clean it, they can’t get 3 footers in. Can this pit serve as a 2nd access point? If they pull the pipe through there, can they hook it up to the Y connector? Will it require breaking more of my basement floor open to do this? I guess I’m mostly wondering if this is a feasible option and what things I need to be aware of or consider.
I would rather not have to dig up my whole front lawn, side walk, and street if I don’t have to. My neighbor had to for his house 2 months ago and it was a mess. The city wouldn’t even let him put the same dirt back. He was required to get special fill that wouldn’t settle as much.
Hi,
Really it has to be determined by the camera inspection whether the line is a viable candidate for pipe bursting first.
You say they could not get a 3″ cutter through which makes me wonder if the cable for pulling the bursting head can get through as well. If they can get the camera to go through the bad area then the cable will go through.
There basically needs to be a hole providing access to the line at each end.
It is possible the pit in the basement could be used but it may have to be enlarged.
If the line going out is encased in concrete it would not be be a viable option and a hole would have to be dug outside the foundation to provide access.
Thanks for your comments,
Redwood
I’m a Realtor representing the buyer of an older home. The 1940’s concrete sewer pipe is just clean as a whistle unitil about 100ft out from the house where there is about 2″ offset and a small cavity has formed. The camera would not hop over the ledge. Water flows though and there are no reports of back-up problems. There is also a belly at this point in the line which may have formed as a result of the offset. It turns out the sewer runs out the side down the hill and through the neighbors yard and at some pt they connect and head on to the street, which is still a fair distance away (e.g. 75ft). We found the offset to be located either right at the edge of an addition which was added to the back of the neighbors house, or under the addition. It seems logical that when the “unpermitted” structure was built right over the sewer line, the weight of the foundation may have resulted in the offset.
So I’m wondering if there are any options to insert something (a sewer stint) to bridge the offset, as opposed to these methods that replace the entire line?
Thanks,
Hi Victor,
I’m afraid that a 2″ offset in a 4″ line does present a situation where about 1/2 of the pipe is blocked making the line unreliable at best. The leakage at the offset will more than likely wash out additional soil causing the offset to worsen over time. The line probably is not a candidate for any of the trenchless technology but that would have to be decided by the sewer contractor upon viewing the video inspection. It is possible that pipe bursting may smooth out the offset and the small belly behind it but it is a risky proposition at best. Pipe relining won’t do anything for you in this case as it conforms to the existing pipe and doesn’t change anything.
What would it take to intercept the line before it goes under the neighbors home then reroute the line alongside the addition to where it can tie back into the line? That is probably the best option. What has been proposed so far as a method to repair it? In many communities two homes sharing a single line would be an issue. What do the local building officials want done in this case? It seems a backup or, mechanical problem in a shared line always brings out the worst in people in terms of fault and responsibility often causing considerable delays in fixing a problem. Building officials usually seek to avoid problems by insisting on separate lines for each house. They may demand that if any work is done on the line that a separate line be run to the city sewer.
Redwood
Thanks,
That’s what I figured, and yes it would be possible to re-route the line around the addition which was built over the line. It seems pretty obvious the addition caused the problem, and hopefully the owner would share in the expense, even if the addition was added several owners earlier. At this point, we don’t know if the tie-in is before or after the offset. That’s a good question about sharing the line, and will need to be explored further.
Do you have any idea what king of price tag would be associated with digging a new trench around the addition to re-route the line, probably talking 100ft by the time you account for where to tie in up the hill (to avoid anything more than a 22.5 degree turn)?
We do expect the situation to get worse over time, but have no idea if that is 2 years or 20 years before there are backing up or a complete failure. Right now we are thinking to use it until the back-ups start, which would indicate it’s time to take action. Do you agree?
One more thing. The cavity where the offset occurs is about the size of a softball. If a liner could be installed in just this stretch to bridge the gap where the offset occurs, and if it was rather rigid and slick, wouldn’t that potential prevent the further deterioration in the cavity? If it didn’t clog up, which presumably is not currently a problem, maybe this would hold indefinitely?
Two more things: Do all of these techniques require access from both sides to pull something through? It sure would be nice to insert from the toilet side a 3-4ft piece of something that would shore this up.
Victor
Hi Victor.
Rerouting the line is probably the best bet and you will have to investigate if the local building officials have any demands concerning the shared line.
Pricing is determined by many factors depth and length being the main ones along with on site conditions. Also pricing varies widely in different areas so you really need to get pricing from local contractors.
I would expect it to get worse over time and ultimately fail. But that said when the transmission in my van started acting up and the guy at the transmission shop said it had about 6 months to go before it went out, I waited! Save your money the time is coming!
The off set reduces the pipe diameter by about 50%. This in most cases is enough to cause problems. I would want the full diameter restored. In a situation like yours the hub of the pipe where the sections join together over lapping has broken. The pipe is broken and weak shearing would probably continue.
Pipe bursting which may work in your situation (contractor evaluation needed) requires a hole on each end of the line being replaced. One hole where the line is fed in and the other where it is pulled from. Relining can work from a single hole but that will probably not be advisable in your situation.
Redwood