My incoming water pipe is copper and it is a brand new installation with no leaks. But due to the hot humid weather (even in the basement) it sweats due to condensation. Should I insulate it?

The problem is last year I insulated some copper pipes only to find a year later that they all corroded due to the water trapped between the pipe and the insulation.

  • Insulation can cause too much moisture on the pipelines and this moisture can cause corrosion, especially to copper and stainless steel pipes.
    – plumbing
    Aug 27, 2011 at 11:55

3 Answers 3


I wouldn't bother insulating your incoming cold water pipes. If your basement is warm, the water will warm up a little passing through it, but the solution to that -- if you need it -- is to let the cold water run for a little until you're see water that hasn't been sitting around in your pipes getting warm. I say "if you need it" because I generally don't care what temperature my cold water is: drinking water for me comes from a pitcher in my fridge; tap water is used for washing food, mixing with hot water for bathing, or watering plants.

If you're concerned about the condensation from your pipes dripping onto things, I'd be more inclined to get a dehumidifier and run it while you've got this hot, humid weather.

  • I'll have a dehumidifier for sure. Maybe I'll leave the pipes alone after all.
    – Peter Q
    May 5, 2011 at 22:30

The only reason to insulate your incoming water feed is if there is a risk of it freezing during the winter, in which case it's essential.

If it's properly insulated - i.e. there's no gaps in the insulation and there's no gap between the insulation and the pipe then you shouldn't have a problem with condensation as there'll be no way the warm moist air can get to the cold pipe.


Although counter intuitive, DO NOT INSULATE copper pipes...hot or cold. It will result in corrosion. When the hot water is not being used (at night for instance when everyone is asleep) the copper hot water supply pipes are the same temperature as the cold water pipes. If there is moisture in the air, condensation will form on the exterior of both pipes. If the pipe is insulated, the condensation will not evaporate and will start to corrode the exterior of the copper pipes, regardless if they are hot or cold supply lines.

  • Isn't the better solution to simply keep your indoor climate regulated so you aren't condensing water indoors to begin with?! Jan 15, 2021 at 21:48

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