PVC is the best sewer pipe material available. It does not rust, roots cannot grow through it, and the walls are rated for 75 to 100 years. If your home was built after 1985 you almost certainly have it, and that is good news.
So here is the uncomfortable part. In our experience the pipes that fail early are not the clay ones. They are the PVC ones, and they almost never fail in the middle of a length of pipe. They fail at a glued joint.
What we see in the field
We have never had to go back and deal with a failed CIPP liner. We have dealt with multiple failed PVC lines, and in every one of those cases the pipe itself was fine. The connection was not.
Two weeks before writing this we lined a PVC sewer in a commercial building. Not because the pipe had deteriorated, but because the glued connections had let go and fixing them properly would have meant tearing up parking lot and roadway. Lining a pipe that is only 20 or 30 years old feels strange until you see the camera footage.
Why a glued joint fails when the pipe does not
Joining PVC is a two step chemical process, and both steps are easy to get wrong in a trench.
Step one is primer. It softens the surface of the pipe and the inside of the fitting so the cement can fuse them. Skip it, or miss a section going around the pipe, and you get a joint that is stuck rather than fused.
Step two is cement. Applied over the primed surface, the two pieces are pushed together and the plastic welds.
Here is the failure nobody expects. Primer acts as a lubricant. When you push a primed pipe into a primed fitting, the pipe wants to slide back out. If the installer does not hold it in place while it sets, it backs partway out on its own.
From outside, that joint looks finished. The pipe is in the coupling. The cement is visible around the edge. Everything reads as correct.
Inside, the pipe is only seated part of the way, and there is a gap where full contact should be. That gap is where the failure starts, and it can sit there for two decades before anything shows up in the house.
Why it happens more in a trench than in a basement
None of this is a knock on the installers. The conditions are the problem.
Gluing PVC properly wants clean, dry, reasonably warm surfaces and enough time to hold the joint. A sewer lateral gets installed in a trench, often in mud, often in cold, frequently with a crew that has a schedule to keep. Dirt on the pipe end or moisture in the fitting is enough to compromise a joint that otherwise looks perfect.
Multiply that by every connection in the run. A typical residential lateral has several. Each one is an independent chance for the same mistake.
The real difference: mechanical versus chemical
This is the part worth understanding, because it explains why lining outperforms new pipe in a way that sounds backwards at first.
A glued PVC line is a series of separate pieces held together by chemical bonds. Every joint depends on a chemical reaction having gone correctly, in field conditions, decades ago, and on staying stable ever since. You cannot inspect that from outside. You find out when it fails.
A cured in place liner is one continuous piece. There are no joints, so there is nothing to separate. The only way it fails is if the pipe itself is physically damaged, which is a mechanical failure and a much higher bar.
In construction the general rule is to trust a mechanical connection over a chemical one wherever you have the choice. A liner removes the chemical dependency from the run entirely.
That is why we would stand behind a properly installed liner over a properly installed PVC line. Not because PVC is bad pipe. Because a liner has fewer places to go wrong.
What this means if you have PVC
Do not panic and do not replace anything. Most PVC laterals are fine and will outlive their owners.
What is worth knowing is that having PVC is not a reason to skip a camera inspection. Homeowners tell us all the time that their line cannot be the problem because it is newer pipe. Newer pipe with a bad joint behaves exactly like old pipe with a crack.
Signs worth taking seriously regardless of material:
- Slow drains in more than one fixture rather than a single sink
- Gurgling in a toilet when the washer or shower runs
- Backups that clear and then return within weeks
- A sewage smell in the yard or basement
- Unusually green or soggy patches in the lawn with no sprinkler nearby
A camera pass answers it in twenty minutes. If the joints are sound you have peace of mind. If one has separated, catching it while the pipe still holds its shape means lining is on the table instead of excavation.
Can a PVC line be lined?
Yes, and we do it. PVC lines very well because the pipe holds its shape, which is exactly what a liner needs from a host pipe.
It is often the better answer when the failure is at the joints. Repairing a bad connection means digging to that specific point, and if the point is under a driveway, a parking lot, or a road, the restoration cost dwarfs the repair. A liner seals every joint in the run at once, from access points, without opening the surface above.
That is what we did on the commercial building. The pipe was young, the joints were not, and digging was going to cost more than the pipe was worth.
Find out what you have
We include a camera inspection free on service calls. You watch the screen with us, and if the line is sound we will tell you that and leave.
If a joint has let go, you will see it on the footage before anyone talks about price.
Contact us or call 218-409-6356.