Hot take: those flex supply lines under sinks cause more leaks than they fix

I used to swear by them. Easy install. No soldering. Then my buddy in Phoenix showed me a corroded braided line that burst after 3 years. The rubber inside degrades faster than old school copper. Now I only use rigid copper supply tubes under my kitchen sink. Anyone else ditch the flex lines yet?

2 comments

2 Comments

drew_chen5d ago

Hold up, I gotta push back a little on the rubber degrading faster than copper thing. That's not really how it works for most people. Those braided stainless lines have a rubber liner, yeah, but it's usually EPDM or something similar that holds up way better than old rubber hoses. Copper can actually get pin holes from aggressive water chemistry or electrolysis if you got galvanized pipes nearby. I've seen copper lines fail from vibration rubbing through at the nut too. I'm not saying rigid is bad, but the flex lines have a much better track record now than they did ten years ago.

stella_foster5d ago

You mentioned "flex lines have a much better track record now than they did ten years ago" and I think that's fair, but I'd also point out that a lot of that improvement is because manufacturers changed the rubber compound in the liner after a bunch of failures in the 2000s. The thing nobody seems to talk about though is installation torque. I've seen more flex line failures from people overtightening them with a wrench instead of hand tightening plus a quarter turn. That crushes the rubber liner at the fitting and it cracks from the inside out years before it should. Your mileage may vary but I always tell folks to read the instructions that come with the braided lines, not just wing it.