How long do pipes really last under pressure?

- I’ve done a couple full-house PEX swaps after catastrophic leaks, but honestly, it’s a huge job. You’re right - sometimes you just trade old headaches for new ones.
- PEX is fast and flexible, but if you don’t use the good stuff (and sleeve it where it’s exposed), you’re asking for trouble down the line. I’ve seen attic runs turn brittle in five years flat.
- Copper’s a gamble too, especially with weird water chemistry. I’ve pulled out 40-year-old pipe that looked pristine, and then found pinholes in stuff from the 90s.
- Pressure testing is non-negotiable for me, even on small patches. Had a client once who skipped it, only to find a slow drip behind new drywall a month later... not fun.
- Full replacement makes sense if you’re already opening up a lot of walls, but if you’re just chasing one leak, patching can buy you time - just know you might be back in there sooner than you’d like.

Ever run into those old galvanized lines mixed in with copper or PEX? That’s always a fun surprise...

Galvanized and copper together is like a time bomb, honestly. I opened up a 60s ranch last year and found this Frankenstein setup - galvanized main, copper branch lines, and someone had even tossed in a few PEX patches. The transition fittings were... creative, let’s say. Ended up with rust flakes clogging aerators all over the house.

Here’s how I tackled it:
1. Traced every line, marked what was what (color-coded tape helps).
2. Prioritized the worst runs - galvanized that was already flaking inside had to go first.
3. Used push-fit couplings for temporary connections while we worked, but swapped them for proper crimped joints once we committed to PEX.
4. Pressure tested *every* section before closing anything up.

Honestly, patching bought us a couple years, but when you start mixing metals like that, corrosion just speeds up. If you’re already opening walls for something else (like insulation or wiring), it’s worth biting the bullet and doing a full swap - less waste in the long run too.

And yeah, attic PEX is risky unless you sleeve and insulate it well... learned that one the hard way during a heat wave.

Man, I feel this. I’ve seen setups where it’s like, “did every decade just add their own favorite pipe?” That mix of galvanized and copper is just asking for trouble - those transition points are always the first to go. You nailed it with:

Honestly, patching bought us a couple years, but when you start mixing metals like that, corrosion just speeds up.

I get wanting to patch and keep things limping along, but it seems like you end up chasing leaks and clogs forever. The color-coded tape idea is smart - I usually just scribble on painter’s tape but that gets confusing fast if you’re in a crawlspace.

On the attic PEX thing... totally agree about the risk. I had a neighbor whose lines literally burst during a cold snap because they weren’t insulated well enough. Insurance nightmare. These days, I’m leaning towards doing full runs of PEX when possible, but I always wonder how it’ll hold up in 30+ years. Galvanized lasted what, 40-50 before turning into rust spaghetti? Guess it’s all about picking your battles (and hoping the next owner appreciates the work).

Mixing metals is always a time bomb, in my experience. I once bought a duplex where someone had patched copper into old galvanized using a dielectric union… except they skipped the union and just joined them straight up. Fast forward three years: pinhole leaks everywhere, nasty rust stains, tenants calling nonstop. Ended up just biting the bullet - full PEX repipe. It’s not cheap, but chasing leaks is way more expensive long-term. I still wonder about PEX longevity too, but at least it’s not rotting from the inside out like old galvanized. Picking your battles is right... sometimes you just gotta rip the bandaid off.

It’s wild how often the “just patch it” approach comes back to bite people. You nailed it with this:

sometimes you just gotta rip the bandaid off.

I get the hesitation - full repipes are a huge hit upfront, but chasing leaks is like playing whack-a-mole with your wallet. PEX does raise some questions about long-term durability (especially with UV exposure or certain chemicals in the water), but compared to the corrosion roulette of mixed metals, it’s a relief.

I’ve seen similar issues in older homes where folks tried to save a buck by mixing copper and galvanized. Even with dielectric unions, you’re still introducing a potential weak point if installation isn’t perfect. Honestly, sometimes the most eco-friendly choice is the one that prevents waste and constant repairs down the line.

Curious if you noticed any water quality improvements after switching to PEX? Galvanized pipes can leave water tasting a bit… metallic, in my experience.