I’ve read mixed things about whether it narrows the pipe enough to matter.
I had the same concern before I did mine. Honestly, I didn’t notice any real change in water flow after the liner went in—if anything, it seemed a bit smoother since the liner covered up all the rough spots where roots used to catch. As for root maintenance, I still do a root killer flush once a year, but haven’t needed to snake it since the liner. Used to be every six months with the old clay. Definitely less hassle now.
I’ve heard similar things about liners possibly reducing the diameter, but from what I’ve seen, the difference is pretty minimal—usually just a few millimeters. Like you said, the smoother surface seems to help with flow, especially compared to old clay or cast iron that’s all pitted and rough inside. I’m curious, though—did you have any issues with offsets or weird bends in your line before you had it lined? I’ve read that liners can sometimes bridge small gaps, but if there’s a big offset, it might not seal as well. Wondering if anyone’s run into that or had to do extra prep before lining.
I’ve read that liners can sometimes bridge small gaps, but if there’s a big offset, it might not seal as well.
That lines up with what I’ve seen on jobs. Liners are great for minor offsets—like, if the joints have shifted just a bit, the resin usually fills those in and you get a pretty good seal. But once you start dealing with bigger offsets or sharp bends, things get trickier. I had a customer with an old clay line that had a good inch-and-a-half offset at one joint. The liner ended up bridging it, but you could still feel a little “bump” when we ran the camera through after. Not ideal, but it was watertight.
Prepping is key. Sometimes we’ll dig up and repair the worst spots before lining, especially if there’s risk of collapse or a big gap where roots keep getting in. Otherwise, you’re just putting a band-aid over a bigger problem. And yeah, the smoother surface really does help with flow—seen some pipes run better after lining than they did brand new, just because there’s nothing for stuff to catch on anymore.
Definitely agree about the prepping part. I learned that the hard way when I tried to cheap out and just get a liner put in without fixing a big dip in my old sewer line. The liner “bridged” it, but like you said, there was still a bump.
That’s exactly what happened for me too. It worked, but I’m always half-waiting for something to snag there.“The liner ended up bridging it, but you could still feel a little ‘bump’ when we ran the camera through after.”
Honestly, if you’re watching your wallet (like me), it’s tempting to just go with the liner and hope for the best. But after shelling out for a second repair a couple years later, I’d say it’s worth fixing the worst spots before lining. It stings up front, but probably saves money (and headaches) down the road.
Also, totally agree about the smoother flow. After lining, stuff just glides through—no more mystery clogs every few months. Still, if you’ve got those big offsets or roots coming back again and again, sometimes you just gotta bite the bullet and dig. Not fun... but neither is another plumber bill.
Yeah, that “bump” feeling is the worst—like you’re just waiting for a paper towel or something to catch. I get wanting to save cash, but you nailed it: fixing the big dips first really does pay off. Been there, learned that lesson the hard way too. Sometimes you just gotta dig, even if it’s a pain.