PVC heating wraps

[bobsav2121]

I have a 3 inch PVC septic drain pipe that has a low spot in it and during
very cold weather the standing water in it sometimes freeze's.
My question is can those electric heating cables sold to keep pipes from freezing be used underground on PVC pipe ?

If so do you think it would work.

Been trying to get someone to re-lay the pipe but no one seems to want the job.

Thanks

Bob

[plumguy]

If you go through the trouble of digging it up for a cable then I would just replace the section of pipe that needs replacing. If you don't feel comfortable replacing it then call someone once the digging is done, the job might be a litttle more appealing then!

[bobsav2121]

I've had it dug up for several weeks so that the contrators can see what
the problem is and everybody claims that are either too busy or can't do the job.

[plumguy]

Can you post a picture and maybe we could walk you through the replacement, that is if you can or want to do the job. In a deep freeze I'm not sure how effective heat tape would be, especially taking in to account the thickness of pvc.

[Gary Swart]

I wonder if it would be possible to take the sag out of the line just by raising it and filling under it. Even if you put a new section of pipe in the trench you will have to fill in so that pipe is at the proper slope. If it isn't possible to do remove the sag that way, why not cut the section out, grade the trench, and reinstall the original line using couplings. If the section of pipe is long enough, you could get the end of the pipe into the second coupling by lifting the pipe a few inches several feet on each side of the joint-to-be. This should give you some play in the line to get it started into the coupling. It would take some help, but I've use this technique on smaller pipe. If th digging is done, most of the hard work is already done.

[plumguy]

I don't think you'll fix the dip in the pipe with dirt unless it is a thin schedule. I think slip couplings would be my choice in this type of repair.