The drain pipe for my kitchen sink is leaking. My house was built in 1965. All the fittings are brass. The pipe is type "DWV" copper. Our water is VERY high in calcium, if that matters. I've lived here 30 years and have never been able to get the softener to work right. The pipe connecting the kitchen sink to the main sewer is in attrocious condition, but I can't find a leak anywhere else. It's about a 12 foot run with NO fall. The first 3 feet are rotted through. The rest is soft on the bottom.

My main question then is: What is the expected lifetime of this stuff? I really can't afford to replace any more than that leaky section if I don't have to, but I don't want to be replacing little bits here and there for the next 10 years. Is it typical for the pipes from the bathroom sinks to last decades longer than the kitchen sink pipe?

All the drains in the house tie into a 3" manifold (in the finished ceiling above the bathroom in the basement) that services the two toilets above. There is no fall in any of the drain pipes or the manifold as far as I can determine.

If it all has to be replaced, what is best, plastic or copper? Can all the brass fittings be reused? Please help! Thanks!

In your case the lifespan of the copper is about 50 years. I would replace all of the kitchen drainage with PVC.



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You are describing a classic scenario of a copper drainage system on untreated private well water. Combine the two with 30-35 years of wear and you end up with a system that needs to be replaced. Yours has been compounded due to a lack of proper fall built into the system.

You are at a point where you will have to decide between replacing the system in a once-and-done manner or piecemeal it out over time. If you opt for the latter, you will pay two to three times, possibly more, the cost of doing it all at once.

NC, I have seen copper DWV fail in under 50 years on municipal water under certain conditions. 50 years on untreated well water is a stretch.

salt eats copper. if there is a water softner injecting salt into you water supply then all bets are off as to how long the copper drains will last.
at least all the venting should be fine. it may be galvanized as that was the norm back then.
so, change as much as is practical to plastic. keep all the old copper and fittings and sell them for scrap.

There is NO "salt" in soft water, it is just Sodium. Copper lines will be damaged if you use drain cleaners on a routing basis. Which could be one reason the kitchen deteriorated before the lavatories.

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