My house has 2 sump pumps that run every minute or so on wet days (and sometimes dry ones). Even with a French drain, there is constant water coming into the sump pits.

They are both enclosed with a radon/sump cover that keeps some of the noise down but the pumps are just below my TV area which is why I'm here.

I put in some insulation batts with kraft paper barrier in the ceiling above the pumps with the kraft paper towards the subfloor. It has made an improvement, but I can still hear it run when sitting upstairs.

I just purchased some 3/4 inch rigid foam insulation (with one silver side) and was going to start tacking it up to the studs, but I thought about it creating a moisture trap. I need some guidance.

I was planning on doing the whole ceiling (only 36" wide x 12 feet or so) but not worrying about it being perfect insulation but more sound dampening. The rest of the basement is finished, but this part has exposed poured walls.

Recommendations? Pic

  • Sump pumps probably something you want to hear. Do not hear for a time is a way to know to check on them, they do fail once in a blue moon. That pump in the picture might be somewhere you do not check often enough.
    – crip659
    Dec 21, 2022 at 22:55
  • 1
    Do you notice a water-hammer thump at shut-off or a motor whine more? If it's motor whine, your best bet it to do something about that brick corner. A speaker against a wall is twice as loud as one in the middle of the room, and one in the corner is 4X louder. Put a roll of carpet padding or carpet in that corner. Put a rug down on that concrete floor. Hang towels, blankets, ceiling tiles, cardboard (anything but bare) on the wall to cut down reflection; waves have to pass though them twice (primary and reflected), so that will help a lot. Get the room performing better on the clap echo test.
    – dandavis
    Dec 21, 2022 at 23:04
  • That plastic cover acts as a Amplifier, stop it
    – Ruskes
    Dec 22, 2022 at 3:29

1 Answer 1


You want mass and an air gap. Roxul safe N sound will work way better than fiberglass for this application. If the still isn't enough then you can hat track the ceiling and put in a layer of drywall.

Do you just hear the startup / shutdown of the sump or are you hearing the pumping or do you hear the water flowing / dripping into the pit?

I had a sump pit that had the drip issue and I put in pipe that takes the inflow to the bottom of the sump so that water isn't water falling and is just flowing.

  • did you pierce the inflow pipe on the way to the bottom of the pit? If not, you can get a vacuum lock effect like a cat/plant auto-waterer, which would be bad.
    – dandavis
    Dec 21, 2022 at 23:22
  • I didn't pierce the inflow pipe... it comes from the perforated pvc perimeter drain so can't imagine a vacuum lock... Dec 22, 2022 at 0:06
  • Thanks for the replies. The sound is just the pump starting and stopping. The one that I hear the most is a heavier duty pump (2hp Barracuda). That pit was added after the house was built, and its discharge is through the base of the wall instead of through the cement. It is only loud over that one pump, but I can hear the secondary one kick on sometimes, but the 2hp pump runs the most often and is the loudest.
    – Sean
    Dec 22, 2022 at 2:55
  • 1
    This. Buy a bundle of rock wool. Frame up a little box that goes over the pump. Stuff it full of rock wool. The rock wool doesn't care about getting wet. Eventually the framing will rot, but that's going to be years and years of silence out. Then get a moisture alarm, because not hearing the pump run means you won't know when it failed.
    – KMJ
    Dec 22, 2022 at 4:20
  • I'll use the foam board to line the concrete walls next to the pump to cut down on echo, and build something to go over top of each pump. I originally had a 3/4Hp Zoeller pump in there but it was installed too close to the base of the sump and clogged with rock and basement flooded. Before realizing the rock issue, we figured the amount of water was too much for that pump so we bought a 1Hp Barracuda and installed it. I'm wondering if it is too heavy duty for the size of the sump. It takes less than 2 seconds to clear the water and turn off. The Zoeller is much quieter in secondary pit
    – Sean
    Dec 22, 2022 at 14:13

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.