How long do pipes really last under pressure?

I get where you’re coming from with insulation and checks, but I’ve actually had the opposite experience in my 1920s place. Insulation helped a bit, but the real game changer was replacing the worst of the old galvanized runs—even just one or two sections at a time. The thing is, those pipes corrode from the inside out, so sometimes you can’t see how bad they are until it’s too late. I found a section that looked fine on the outside but was basically paper-thin inside.

For crawlspaces, I started using heat tape along with insulation, especially on copper. PEX is supposed to be more freeze-resistant, but I’ve seen it kink or get brittle if it’s not supported right. Honestly, mixing materials has its own headaches—dielectric unions can help with corrosion between copper and galvanized, but they’re not foolproof.

If you’re sticking with patchwork for now, I’d suggest at least pressure testing before winter and checking for any signs of rust or leaks after big temp swings. Sometimes it’s less about pressure and more about those hidden weak spots... learned that one the hard way under my kitchen sink last year.

Totally agree on the hidden corrosion—had a “fine” looking pipe burst on me last winter, and it was a mess.

The thing is, those pipes corrode from the inside out, so sometimes you can’t see how bad they are until it’s too late.

Title: How long do pipes really last under pressure?

I keep hearing about hidden corrosion and it’s honestly making me second-guess every “good” pipe I see in this place. The inside-out thing is wild—like, you think you’re safe until suddenly you’re not. I’ve been reading up on pressure testing, but I’m not sure how often people actually do it unless there’s already a problem. Is it something you’d do as a routine check, or only if you suspect an issue?

Mixing materials is another thing that’s got me scratching my head. I know it’s not ideal, but sometimes the budget just doesn’t stretch to a full replacement. I patched a section with PEX next to old copper because it was the only way to get water back on before work the next day. Not sure if that’s going to bite me later, but so far, so good.

Curious if anyone’s had luck predicting when pipes are about to go, or is it just a roll of the dice? I’ve heard some folks say galvanized lasts 40-50 years, but then others have horror stories at 20. Does water quality make that much difference? My neighbor swears by annual flushes, but I’m skeptical that does much for old metal lines.

Would love to hear if anyone’s actually caught a problem before it turned into a disaster—or is everyone just waiting for the next surprise leak?

Mixing PEX and copper isn’t ideal, but honestly, I’ve seen it hold up fine in plenty of remodels—just keep an eye on the fittings. Water quality absolutely matters, especially with galvanized. Hard water can eat pipes from the inside way faster than you’d expect. Pressure testing’s great if you suspect a leak, but I wouldn’t call it routine unless you’ve got a really old system or notice pressure drops. Annual flushes help a bit with sediment, but they won’t stop corrosion in old metal lines. I’ve caught a few pinhole leaks early just by noticing tiny green stains or damp spots before things got ugly... sometimes it’s just luck, though.

I’m right there with you on the water quality thing—my last place had super hard water, and I swear the pipes aged faster than I did. I’ve got a weird mix of PEX and copper in my current reno, and honestly, it’s been fine so far. The fittings do make me a little nervous though... like, are they just waiting to surprise me one day? I do try to check for those green stains too. Sometimes I feel like a detective looking for clues before the real drama starts.