Ask Your Question

Angie's List Answers is the trusted spot to ask home improvement and health questions and get answers from service companies, health providers and consumers. For ratings and reviews on companies in your area, search Angie's List.

Top 30 Days Experts
Rank Leader Points*
1 kstreett 240
2 Guest_9020487 110
3 Guest_9190926 105
4 GoldenKid 100
5 ahowell 95
6 KnowledgeBase 95
7 skbloom 80
8 Guest_98024861 70
9 Guest_9311297 70
10 Guest_9400529 70

*Updates every 4 hours

Browse Projects By Category

Question DetailsAsked on 9/11/2013

What's the best way to deal with an old sewer line that gets clogged by roots?

Old house (1890s). Sewer line was inspected a few years ago and roots needed to be removed. The line runs under a concrete walkway that we are going to remove and replace this fall. Should we take the opportunity to replace the sewer line? Is that better than doing a "trenchless" repair? Not sure how old the line is, but probably over 50 years (and certainly over 25).

Do you have the same question? Follow this Question

6 Answers


If you are going to remove the concrete anyway I would take the time to go ahead and replace the line. In the process cut the roots as far back as you can and put copper sulfate around the pipe. Any roots that grow back over to the line in the near future will die from the copper sulfate. I did this with my line about 4-5 years ago and haven't had a problem again yet. Hopefully I won't for a very long time.

Todd Shell

Todd's Home Services

San Antonio, TX

Answered 7 years ago by Todd's Home Services


As Todd said if the walk is to be replaced put a new pipe in. Relining the existing pipe will make the pipe smaller and whatever they use to line it will not be as resistant to roots as a PVC pipe of the proper schedule, I would use schedule 40 at the least. I connected to the sewers in my town and abandoned my septic, my sewer line runs about 125 feet to the street and in one spot is barely covered with soil due to ledge rock. That is the only spot I have had problems with and it was not roots entering the pipe but lifting it and breaking a joint. And I believe that it was 20 years since it was done

Answered 7 years ago by ContractorDon


I also would recommend against trenchless repair unless that is necessary because of the cost of rerouting or disturbing important features - reduces line size, can be damaged by ground movements if being put through a cracked sewer line, etc.

You did not say if the line crosses under the sidewalk (in which case only 1-2 panels would be disturbed if dug up in the future) or underneath it all the way along. If that is the case, I woulld move the walk or plan on digging a replacement new sewer line in alongside it (now or when needed in the future - why put a walk intentionally over a line that may have to be dug up at some time in the future ?

You did not say what your line is made of, or what the root situation was, and of course you do not know how old it is. Rather than spend $2-5,000 replacing it now, unless you already know the condition I would spend the $200-350 (depending on whether it has to be routed out first) to get a color camera run through it and check it out. If the pipe is intact and only rootlets are coming in through the joints (as opposed to full-size roots breaking the joints apart), I can't see replacing it now unless it is heavily corroded or broken - get it routed out full diameter with a cutter blade router if grease and soap scum are closing its diameter down or if needed to cut roots, then use RootX yearly - that will kill the roots back and solve future root intrusion problems. Of course, if you want peace of mind and can afford it, then a new line might give you that, but well-laid lines that sdurvive the first 10-15 years commonly survive 50-80 years - unless 1970's-90's black butyl plastic or galvanized steel, in which case typically fail in 25 years or less.

A couple of comments on Todd and Don's thoughts -

If you use plastic pipe, use schedule 40 sewer rated (NOT water pipe) as I think Don said - cost not much more, but more resistant to construction damage, which is how it usually fails - schedule 20 drainfield pipe is pretty light and brittle for underground use, and below recommended thickness for buried sewer pipe though does meet code for many areas.

If you put in a new line and spread copper sulfate to stop root growth, do NOT sprinkle it directly on the pipe as it can damage both plastic and metal pipe - sprinkle it in the bottom foot + of the trench before backfilling starts (bottom and sides), then after the bedding material comes up to 3 inches or so above the pipe, sprinkle full width across there. Easier way - dissolve it in warm water and spray it in a thorough coating with a plastic weed killer sprayer tank - will be bright blue so pretty easy to see where you got coverage. More details on using it by googling this search phrase - concentration of copper sulfate to kill tree roots

Answered 7 years ago by LCD


Thanks for the replies. I have now had a camera run through the line. It is clay and appears to be in excellent condition -- no roots or other obstructions. I think I'll leave it be!

Answered 7 years ago by Guest_985625026


It is nice when the person asking the question gives feed back!

I thought that might be the type of pipe you had do to the age of the house you gave. A clay pipe is probably the second best type to have in my opinion aside from the number of joints. PVC was not around then. As long as you are careful with heavy traffic over it while doing your walk (no cement trucks or equipment) it will out last you probably. And yes it is most likely well over 25 and probably more than 50 years old. I think if I remember correctly there still pipes in service that were put in by the Romans. Who says new is always better.

Answered 7 years ago by ContractorDon


Ditto to Don's comment on being nice to get feedback on responses - lets us know we are being helpful and the questioner actually saw the reply, and if they thought it was helpful.

Like Don, I suspected clay pipe - it last until it is broken - basically does not wear out, so it sounds like the camera runn saved you a few thousand $ and gave you some piece of mind.

On Don's comments on no heavy truck or concrete trucks over the pipe - as long as it is buried at leat 2 feet to the top of pipe should be no problem as the load is well spread out by that depth, if you know how deep it is. Should be at least to frost depth in your area, if it was installed to code, if you are in an area with real winters.

On your construction - make sure the contractor gets utility locates (free) because TV, electric, gas, and phone are typically only 6-12 inches down, so if your soil is rocky heavy trucks running over them can puncture them, or if boggy or soggy can stretch and break them - they should be covered with a timber cover (3/4 ply reinforced by 4-5 2x4's nailed lengthwise to the bottom works well) if loaded concrete or dump trucks have to run over them. Small loaders like bobcats or tracked vehicles not a problem as long as they are not twisting on top of them.

Answered 7 years ago by LCD

Related Questions

Terms Of Use
Privacy Policy