Relining Pipe for Root Intrusion

[rootsinmain]

I am looking for some advice on relining sewer pipe. The house I live in was built in 1965, I recently moved in. We have had two clogs in 3 months. After first clog, I started using root kill from HD hoping it will kill the roots but after 3 months, we got second clog. Second clog pulled out lots of roots so now situation is bad!!

Already did the camera inspection and here are the results.
We have cast iron clean out and rest of the pipes are clay. about 20 ft of pipe is damaged and has roots.

I have had two plumbers come out, first one said - Replace the damaged line with some PVC pipes and estimate was about $4k and if I do digging, replacing line would be about $1k.

Second guy told me to re-line pipe using some fiber glass material. He never said the word "epoxy" but all my search on web lists re-lining pipes using epoxy material. Two re-line 20 ft pipe, estimate was $2400 and re-line entire line about 60 ft, $5k!! He said it would last 100 years but I am not too sure.

I am looking for some advice on if lining pipe is good or what is cost and reliability on those?

[LazyPup]

Although the techniques for are relatively new many municipalities are having tremendous success with re-lining the pipes, however it must be understood that when considering a municipal main there are many factors the homeowner would never be confronted with.

Often the municipal sewer mains share a roadside easement with water mains, direct buried electrical mains, gas mains, telephone and cable communications lines and in some cases even live steam headers, not to mention that in order to access these pipes they have to begin by rerouting the traffic on the streets, which in turn will have a tremendous impact on the local businesses, and in most cases it would involve even repaving the entire street. Needless to say, any method that would allow them to reline the pipe without disrupting the other services would save the municipality countless millions of dollars.

We must also consider the diameter of the pipes involved. In most cases the municipal mains will be a minimum of 8” pipe and ranging upwards to 5 or 6 feet in diameter. In this case a minor 1/8” or even and inch of buildup on the inside of the pipe would have little to no effect on the total volume or velocity of flow. On the other hand a typical residential line is only 3” or 4” in diameter so any additional buildup on the inner wall of the pipe can be a factor that must be considered.

You state that your existing line is a vitreous clay tile and you have had problems with tree roots. From that we can conclude that not only have the roots gotten into the pipe and caused direct clogs, it is almost a certainty that other roots have grown over or under the pipe and as those roots mature they not only cause severe strain on the pipe, they can also cause the pipe to shift its position, forcing joints open or altering the pitch of the pipe. In this case, even though re-lining the pipe would make it water tight and somewhat impervious to root infiltration, it must also be understood that it can do nothing to correct an improper pitch, which results in retarding the velocity of flow.

Based upon the estimates you quoted it would appear that the cost of relining is about 60% of the cost of replacing the pipe. In this case I would give serious thought to replacing the pipe rather than relining.

You also stated that your total run in 60’ however the camera revealed that only about 20’ of the pipe is damaged at this time. One thing is certain, the trees are constantly sending out super fine roots, generally as small as a human hair to explore the soil in search of water or nutrients. Once one of those roots discovers what its looking for it will then signal the tree to concentrate growth in that direction, so while you may have some success with replacing the damaged section, it would only be a matter of time before the roots find their way into the remaining pipe and you would be confronted with the problem all over again.

With a total run of 60’ you are only looking at three lengths of sched.40 PVC pipe and 5 joints to replace the whole line.

While replacing the line will certainly no doubt require a permit and inspection, unless your jurisdiction has an ordinance to the contrary there is nothing difficult about it, and certainly not beyond the scope of a DIY project.
The first thing you would have to consider is the depth of your line. While the plumbing code only requires the line to be 6” below the average frost depth for your area the local conditions could dictate it to be much deeper, by example, if your house has a basement and if the line runs under the basement floor the burial depth might be 8 or 9’. Generally when working with trenches up to 4’ deep a DIY’er should have no problem, but if you require a deeper trench it might be best to leave it to experts. You certainly wouldn’t want to be crouched down in a deep trench making a joint and have a trench wall cave in on you.

The method that you select to do the trenching is totally dependant upon soil conditions and how much time, money or personal labor you want to put in to the project. Generally a 60’ trench is not beyond the means of a couple men armed with nothing more than a good round point shovel, but if time or personal labor is an issue you may opt for a backhoe or trencher.

Before you do any digging there are a couple legal requirements you should be aware of.
In every community there is a free service that will come out and mark all the underground commercial utilities in your intended dig site. You must call them at least 24 hours in advance so they can send someone to mark the locations. The service goes by different names in different regions, by example, when I worked in Florida it was called “Dig Safe” and here in W. Pa it is called “One Call”. No matter what they call the service you can find the 800 number to contact them by calling your inspectors office, you water or gas company office or your plumber or electrician should be able to give you the number. Keep in mind that you are legally required to have the utilities marked. You can be held both civilly and criminally responsible for damaging a public utility line, not to mention that you could be electrocuted or have gas explosion if you fail to check the location of the lines.

In some jurisdictions you will be required to pull a permit before you start the project.

If you have rocky soil, in addition to the pipe you will also need some fresh sand to bed the new pipe before backfilling. The sand should be compacted about 6” below the pipe, then extend upwards until you have about a 6” covering before pushing the original soil back in the trench.

Depending upon the size of pipe you have, whether it is 3” or 4” the pipe prices range about $3 to $7 per/ft and you have a total of 60ft so if you were to do the digging and labor yourself you should be able to put in an entirely new line for under $1K parts and labor.

[rootsinmain]

Pipe Blasting

Thank you lazyPup for your detailed response. You touched a very good point about pipe shifting from its position. When we did the camera inspection, plumber did mention that pipe has moved down little bit but at the same time, he said re-lining will fix it.

I live in an older neighborhood and we have alley for trash and sewer. Main goes from backyard to alley and depth varies from 4 ft in backyard to 9 ft in alley.

If I dig in alley, I have to get permits and it is 9 ft deep. However, the damage portion is an near alley, plumber 1 suggested, we could just dig there which may be easier as backyard is all concrete!!

Plumber 2 (who suggested re-lining) also briefly talked about pipe blasting with some ABS pipes. He didnt give very much detail about this technique but ball park estimate was about $5-6k and it will replace the entire line without much digging.

I am very much inclined to do replace the entire line but it is lot of money and want to do my due diligence in finding out pros and cons of both techniques.

Couple more questions - anyone here knows about pipe blasting technique and its pros/cons?

What is bothering me is root of problem - source of "roots". We have really tall palm trees and as far as I know palm trees roots grow straight down. There are no other trees around. This question may not belong here knows if palm trees roots can spread horizontally? Will taking down the palm trees help solve the problem.

Thanks for reading all this.

[LazyPup]

There are a number of different methods used for "Pipe Blasting" but in the end, they all produce the same result. The new pipe is literally pushed through the soil eliminating the need to excavate. The common use of this technique is to push a pipe under a roadway, thereby eliminating the cost of rerouting traffic, breaking up a roadway, repairing the roadbed and re-paving the roadway after the pipe is laid.

Generally a residential house sewer line (Line from structure to the septic tank or municipal sewer) is 100' or less and it typically runs under a lawn, where excavating is not a major problem. In this instance when we consider that relining would be approximately 60% of the cost of laying a new line, it then becomes cost effective to consider the new pipe. On the other hand, in your case, you are confronted with the same problem that the municipal sewer lines have. Your pipe is run under a concreted area, therefore you would have to factor in the cost of cutting the concrete for excavation plus the cost of pouring and finishing new concrete when you complete the sewer line. Under these circumstances when all is said and done the cost of the relining would then be perhaps 25% of the cost of replacing the line, which would be a substantial savings.

My singular reservation to relining is that it will slightly reduce the effective inside diameter of the pipe, but here again, you have an older home that most likely has a 4" line. 4" lines are still required if you have the old 3.5 or 5gpf toilets, but if you have the newer 1.6gpf toilets the preferred line size is 3" so a slight reduction in pipe diameter should not cause any significant problems.