Switching out a tub for a walk-in shower: copper vs. PEX pipes?

If you’re really worried about mice, I’ve heard some folks run PEX through conduit or use metal plates where it passes through studs. Probably overkill unless you live in a rodent hotspot.

I’ve thought about the conduit idea, but it seems like a pain unless you’re already running a bunch of lines. Has anyone actually had luck with those metal plates stopping critters? I’m not convinced they’d do much if a mouse is determined enough.

On the copper vs. PEX debate, I get the appeal of copper for longevity, but man, the hassle of sweating joints in tight spots isn’t worth it to me. PEX with crimp rings just feels way less stressful. Curious if anyone’s had issues with water hammer using PEX though? I’ve read mixed things and don’t want to swap out one problem for another.

I’ve used those metal plates a few times, mostly because code called for them, but honestly, I doubt they’d stop a mouse that really wants in. They’re more for stopping screws and nails than critters. As for PEX, I’ve only had water hammer issues when the lines weren’t secured well. Once I strapped them down better, it went away. Copper’s nice but yeah, sweating pipes in a crawlspace is the worst... PEX is just way easier to work with in tight spots.

- PEX is definitely easier to run, but I’m not sold on it being the most eco-friendly option.
- Copper’s got a much longer lifespan and is recyclable - PEX just ends up in landfill eventually.
- I get that sweating pipes in a crawlspace is a pain (been there, done that), but I’d rather deal with that once than worry about plastic aging out in 20 years.
- Water hammer’s less of an issue for me than microplastics or chemical leaching, honestly.
- If you’re thinking long-term and sustainability, copper’s still hard to beat... even if it means crawling around with a torch for a bit.

Dragging a torch through a crawlspace sounds like my personal nightmare, but I totally get where you’re coming from.

“If you’re thinking long-term and sustainability, copper’s still hard to beat...”

Copper’s got that “set it and forget it” vibe, which I totally respect, but I’ll admit - I went the PEX route when I did my bathroom swap last year. I was nervous at first (the idea of plastic pipes kind of weirded me out), but after crawling under my house and seeing how many weird bends and tight spaces there were, the thought of torching copper joints down there just didn’t appeal. Plus, I’ve got a healthy fear of accidentally setting something on fire...

I did a ton of research before deciding. The lifespan thing with PEX kept coming up - some people say 40-50 years, others are more skeptical. But then again, I’ve seen old copper pipes with pinhole leaks from corrosion or bad water, so it’s not like they’re invincible either. What actually tipped me was talking to a plumber friend who said he’d re-do his own place in PEX if he ever had to start over. That stuck with me.

One thing I did do for peace of mind: I used those brass PEX fittings instead of plastic ones, and made sure to keep the pipes away from sunlight and anything sharp. It went in crazy fast compared to sweating copper, and honestly, not having to drag a torch through spider territory was worth it for me.

Not saying PEX is perfect - if you’ve got critters, apparently they love chewing on it (my neighbor found that out the hard way). And if your water is super chlorinated, that can be an issue over decades. But for my setup, the flexibility won out.

Curious if anyone’s actually had PEX fail on them after a decade or two? Sometimes it feels like we’re all just guessing about what’ll hold up best in 30 years...

Never seen PEX fail in the wild after a decade, at least not in any house I’ve worked on. Most of the issues I’ve run into were either from bad installs (kinked lines, fittings not crimped right, that kind of thing) or critters like you mentioned. Squirrels and rats seem to think it’s a snack bar under there. If you don’t have a rodent problem, and you’re not running it through direct sunlight or near anything sharp, you’re probably set for a good long while.

Copper’s nice and all, but I’ve replaced plenty of green, corroded copper too - especially in older homes with acidic water. Those pinhole leaks sneak up on you. Honestly, nothing is totally bulletproof. PEX is just way easier to work with if you’ve got tight spaces or lots of weird angles. Plus, sweating joints when you’re lying on your back in a crawlspace? Hard pass. My knees ache just thinking about it.

Brass fittings are a smart move. I’ve seen the plastic ones crack eventually - usually after someone overtightens them or they get knocked around during install. As for lifespan, I think the jury’s still out on whether PEX will hit that 50-year mark everywhere, but most of the stuff put in during the early 2000s is holding up fine so far.

If something ever does go wrong, repairs are usually quick and cheap compared to cutting out and sweating new copper sections. That peace of mind counts for a lot when you’re the one who’ll be crawling under there again in 20 years...

Anyway, unless your local code says otherwise or you’ve got some unique situation (super high chlorine or nasty critters), PEX is probably going to serve you well. Nothing’s perfect, but at least it won’t burn your house down while you’re installing it.

I hear what you’re saying about PEX being easier, especially in tight spots. I just get a bit nervous about relying on it for shower installs, mostly because of what you mentioned - rodents and possible UV exposure. Even if you don’t have a critter problem now, all it takes is one winter with a mouse in the crawlspace to start chewing. I’ve seen it happen in houses that were fine for years, then suddenly you’re chasing leaks.

“If something ever does go wrong, repairs are usually quick and cheap compared to cutting out and sweating new copper sections.”

That’s true, but I’d argue that with copper, if it’s installed right and your water isn’t too rough on it, you’re less likely to need those repairs in the first place. The upfront hassle of sweating joints is a pain (my hands still remember my last crawlspace job), but once it’s in, copper just sits there and does its thing. You don’t have to worry about plastic fittings getting brittle or lines sagging over time.

One thing that worries me with PEX is the risk of someone using the wrong type for hot lines or not supporting it enough. I’ve seen lines droop between joists after a few years if they aren’t strapped up properly. Also, some folks don’t realize you can’t run PEX too close to recessed lighting or other heat sources - seen a couple installations where the pipe got cooked and had to be replaced.

I’m not saying copper is perfect - those pinhole leaks from bad water chemistry can be a nightmare. But for something like a shower swap where the runs are short and accessible, sometimes I lean toward copper just for peace of mind. Maybe I’m just old-school cautious, but I like knowing exactly what’s behind the wall.

Still, you’re right about nothing being bulletproof. Whichever way you go, taking your time with supports and connections is key. And yeah, brass over plastic every time for fittings - learned that one the hard way after chasing down a slow drip behind tile...

“Maybe I’m just old-school cautious, but I like knowing exactly what’s behind the wall.”

That’s fair, and honestly, I get where you’re coming from. I’ve seen PEX installs go sideways when someone cheaped out on supports or used the wrong crimp rings - suddenly you’re tearing out tile for a $2 part. But then again, I’ve also had to chase pinhole leaks in copper that were basically invisible until the ceiling started sagging. Out of curiosity, have you ever tried using PEX-AL-PEX for shower lines? It’s got that rigidity and better temp resistance, but I don’t see it used much in residential jobs. Wondering if that’s overkill or just not worth the hassle compared to regular PEX or copper.

“I’ve seen PEX installs go sideways when someone cheaped out on supports or used the wrong crimp rings - suddenly you’re tearing out tile for a $2 part.”

That hits home. I’ve been called in more than once to fix a “budget” PEX job where someone skipped the basics. As for PEX-AL-PEX, I’ve used it a couple times - honestly, it’s solid, but overkill for most showers unless you’re really worried about temp swings or want zero flex. It’s a pain to work with in tight spaces, though. Regular PEX with proper supports and fittings usually does the trick, unless you’re dealing with something weird like high-pressure commercial setups. Copper’s great, but those pinhole leaks are sneaky... and expensive.

I get the worry about cheap PEX jobs, but honestly, I’m more nervous about copper these days. My neighbor had to rip out a wall for a tiny pinhole leak - insurance barely covered it. PEX seems less risky if you don’t cut corners... or am I missing something?

PEX seems less risky if you don’t cut corners... or am I missing something?

I get what you’re saying, but I still worry about PEX fittings behind walls. I’ve seen a couple of installs where the crimp rings weren’t on right and it took a year for the leak to show up. Copper’s a pain, but at least you can usually spot bad solder joints right away. Maybe it’s just what I’m used to, though. Anyone else dealing with hard water? That’s what killed my last copper line.

I’ve had the same worries about PEX fittings buried in walls. The stuff is super easy to work with, but if you mess up a crimp or don’t get a fitting seated just right, it’s not like you’ll notice until it’s too late. Here’s how I look at it:

- With copper, you can usually see if you’ve got a bad solder joint right away - either it leaks or it doesn’t. Plus, you can often hear the sizzle if there’s still water in the line (ask me how I know...).
- PEX is way faster and more forgiving, especially in tight spaces. But yeah, those crimp rings can be tricky if you’re not careful. I double-check every single one now, and I’ve started using the expansion-style fittings for anything behind drywall - less risk of a bad seal.
- Hard water is brutal on copper. My old house had pinhole leaks all over after about 15 years. Switched to PEX and haven’t seen any issues since, but I do worry about what happens 20 years down the road.
- If you’re doing a walk-in shower, you might have some access panels or removable sections - worth considering if you want peace of mind.
- For what it’s worth, plumbers around here seem to prefer PEX for remodels now, unless someone insists on copper.

I get feeling more confident with what you know. After chasing leaks in both systems, my trust level is about the same... just different kinds of headaches. If you go PEX, maybe pressure-test everything before closing up the walls? That’s saved me once already.

If you go PEX, maybe pressure-test everything before closing up the walls? That’s saved me once already.

Pressure testing is a must, totally agree there. I’ve seen a couple of PEX jobs where a missed crimp didn’t show up until months later - nightmare scenario. Curious if anyone’s tried those push-to-connect fittings (like SharkBite) behind walls? I know code says accessible only, but I’ve seen folks sneak them in. Worth the risk, or just asking for trouble down the line?

I get why people use SharkBite behind walls - super easy, especially if you’re in a hurry or not keen on crimping. But honestly, I wouldn’t risk it. Code says accessible for a reason. I’ve seen a fitting fail after a few years and tracking the leak down was a pain... ended up tearing out drywall anyway. If you want peace of mind, stick to crimp or expansion and make sure every connection is solid before closing things up.

Totally get the hesitation with SharkBite behind walls. I actually tried one in a spot I could reach, just to see if it’d hold up, and after two years it started seeping. Not a flood, but enough to make me rethink using them anywhere I can’t easily check.

If you’re on a budget (like me), here’s how I weighed copper vs. PEX when we did our bathroom swap last year:

1. Price out both materials. Copper’s gone up a lot, and the fittings add up fast. PEX is way cheaper per foot, and you don’t need as many fancy tools unless you go with expansion.

2. Figure out your comfort level with tools. Soldering copper isn’t impossible, but it’s not exactly beginner-friendly either - plus, open flames in tight spaces always make me nervous. PEX crimping is pretty straightforward once you get the hang of it, and you can rent the tool from most hardware stores.

3. Think about future access. Like you said, code wants connections accessible for a reason. If you use SharkBite or push-to-connect, at least keep them where you can get at them later. For anything behind drywall, I’d go with PEX crimp or expansion, double-check every joint for leaks before closing up, and maybe even snap a few photos for reference.

4. Don’t forget about supports and bends. PEX is flexible but still needs to be secured so it doesn’t rub on studs or move around over time.

5. If you’re worried about resale value or inspector headaches, copper still has that “tried-and-true” reputation... but honestly, most folks are fine with PEX these days as long as it’s done right.

I guess my main takeaway: spend the extra time on connections now so you don’t have to rip out tile or drywall later. And if you’re really pinching pennies, PEX with crimp rings is hard to beat for price and peace of mind - just skip the SharkBites behind walls unless there’s no other way.

Hope that helps someone else thinking through this stuff... I definitely learned some lessons the hard way!

I get where you’re coming from on SharkBites - seen a few fail myself, usually after a couple years. But I’d push back a bit on the idea that PEX crimp is always the safest bet behind walls. In emergency repairs, I’ve run into more issues with poorly crimped PEX than with properly soldered copper. A missed crimp or a bad ring can be hard to spot until it’s too late.

“PEX is way cheaper per foot, and you don’t need as many fancy tools unless you go with expansion.”

True, but if you’re already opening up walls, sometimes it’s worth investing in the expansion tool for PEX-A. The fittings are more forgiving and less prone to leaks over time compared to crimp rings, especially if there’s any movement or vibration.

Copper’s not perfect either - electrolysis and pinhole leaks can sneak up on you, especially in older homes with mixed metals. But if you know how to sweat a joint and have the patience, it’s still the gold standard for reliability.

Bottom line: whichever route, double-check every connection before closing up. Seen too many “budget” jobs turn into expensive headaches down the road...

I hear you on the PEX-A expansion fittings being more forgiving, but I’ve actually had better luck with PEX-B and stainless cinch clamps, especially for DIY. The expansion tool is nice, but it’s a bit of a learning curve and not cheap if you’re only doing one bathroom. With cinch clamps, you can visually check the connection, and the tool’s pretty much foolproof - just squeeze until it clicks.

One thing I’d throw out there: if you’re worried about leaks behind walls, consider running a pressure test before you close anything up. I rigged up a cheap gauge from the hardware store and left it overnight - caught a slow drip I would’ve missed otherwise. Saved me a ton of hassle.

Copper’s great, but sweating joints in tight spaces is a pain, and I’ve scorched more than one stud over the years. For a tub-to-shower swap, I’d lean PEX just for the flexibility and fewer fittings. Just my two cents...

I hear you on the pressure test - caught a tiny leak in my laundry room that way, too. Honestly, I tried copper once and the flux fumes set off my smoke alarm, which was a bit of a circus. PEX-B with cinch clamps just felt less stressful, and I liked not having to drag out the torch. Still, sometimes I wonder about the long-term durability compared to copper... anyone notice any weird taste or smell with PEX after a few years?

Honestly, I get the appeal of PEX - way less hassle, especially in tight spots. But I’ve seen a few older installs where the PEX started to get a bit brittle after 10+ years, especially if it was exposed to sunlight or got hit with some weird water chemistry. Copper’s a pain to work with, sure, but I’ve never had anyone call me back for a taste or odor issue with it. PEX can sometimes give off that plasticky smell for a while, though it usually fades. Still, if you’re worried about longevity, copper’s hard to beat... just wish it wasn’t so pricey these days.

- I hear you on the copper cost - it's wild how much it's gone up.
-

“PEX can sometimes give off that plasticky smell for a while, though it usually fades.”