Author Topic: Reducing the sound coming from a sump pump in a hole in the basement floor  (Read 7537 times)


  • Guest
Greetings, first time poster, just found this forum by accident while using reddit, but it looks like a great resource for making my house quieter.

I installed a sump pump a couple of years back to deal with occasional water issues in my basement -- which I'm in the process of finishing. The pump is doing its job, but the noise it makes wakes me up -- because it is in my utility room which is under my bedroom, so I'm looking for ways to dampen or reduce the sound that escapes the hole the unit is in, or the utility room, or both.

The pump is in a 18" deep hole that I created for it. The hole is covered currently by a piece of 3/4 inch, marine grade, plywood, which has my clothes washing machine sitting above it. It was just random chance that the washing machine was already in the location that I thought was best for the sump pump. There is an opening of about 3" in diameter on one side of the plywood, which allows for a PVC water pipe to move any water up and out of the hole, up the wall, and out of the house. The moving water sound is something I'd also like to reduce it some point, but the pump makes most of the noise so that is my initial concern.

I'd also like to reduce the sound from this unit to other rooms in the basement, not just to the upstairs.

So, I have a couple of ideas that I'm planning to use in conjunction, and I wanted to get feedback from folks here, please.

Starting from the unit and working out, I was thinking of making the lid more soundproof by putting a piece of 1" rigid foam insulation on top of the plywood lid, and then putting another piece of plywood on top of that foam -- then putting my washing machine on top of this. Id' then find some kind of rubberized material that I could wrap around pipe where it comes out of the lid to close any air gaps that sound might escape out of. (by the way, I'd say the pump is similar to a typical shop vac in sound volume).

Next, I'm planning to put 2" rigid foam insulation in all of the stud bays around this utility room (it has to walls to the rest of the basement, and the other two walls are the concrete foundation). The rigid foam would be held in place with dow spray foam. This is something I was already doing for thermal insulation in the basement, and I thought it would also help for sound dampening.

Thirdly, I'd be doing this same rigid foam + spray form in the basement ceiling joist bays.

Finally, I'll be putting up 5/8" sheetrock. I'm somewhat headroom limited in the basement, so I don't want to do any special system between my ceiling joists and my sheetrock, because I just can't spare the 1-3 extra inches such systems seem to need, and there is a chance I might convert this utility room to a combo kitchen/utility room (might do a basement apartment) so I do not want to do anything to reduce the already limited headroom.

Curious what the experts here think of this approach?

Randy S

  • Guest
Ok for starters,,, the lid for the hole....make it very heavy. 1/2" cement board 2 layers and use Mass Loaded vinyl 2#.

For wrapping the pipe use mass loaded vinyl w/ closed cell foam

Now for walls and ceiling.. there are a couple ways to pull this the end you need to make sure the lbs per sqft of the walls and ceiling reach at least 8lbs per sqft minimum.

For the tricks it is best to call me direct so I can share photos and discuss principles.

Randy S.