I'm trying to help out an elderly friend with a plumbing issue. He doesn't know anything about plumbing, and I don't consider myself very knowledgeable in the field.

His sink currently has an InSinkErator Badger 5 garbage disposal that requires replacement. Will the ISE Evolution Compact garbage disposal fit under this sink without modifying the plumbing?

The InSinkErator website claims:

[The Evolution Compact] has the same rough-in plumbing dimensions as Badger models so it can be easily interchanged with any Badger disposal without altering the plumbing connections.

Looking at the diagrams in the manuals, he and I both wonder if this is true.

As you can see, the Badger 5 has a 5" horizontal distance between the two vertical centerlines:

Badger 5 garbage disposal diagram Source: InSinkErator Badger 5 manual

Whereas the Evolution Compact has a 5.75" horizontal distance:

Evolution Compact garbage disposal diagram Source: InSinkErator Evolution Compact manual

There is also the 1.75" difference in diameter between the 2 units to contend with, but I can't tell if that will also be an issue.

Here are 2 photos of the plumbing pipe layout:

Plumbing pipe layout photo 1 Plumbing pipe layout photo 2

Will the InSinkErator Evolution Compact garbage disposal fit under this sink without modifying the plumbing?

If not, what would be required to make it fit?

  • 1
    Nice to see all the info needed to answer the question with focused pictures, and nice to see someone's double sink plumbed properly without a drip pan underneath!
    – jay613
    Jun 15, 2021 at 17:27
  • Is this the photos concerning your other question?
    – user113627
    Jun 15, 2021 at 17:32
  • Already have the replacement disposal? I think you will just have to jump into this with both feet. But prepared to go to a hardware store.
    – user113627
    Jun 15, 2021 at 17:48
  • Is that P-Trap cemented? Its actually a two piece unit homedepot.com/p/NIBCO-2-in-ABS-Hub-x-Hub-P-Trap-C5885HD2/… If you dont have enough wiggle room with the threaded fittings. It looks like getting a new Ptrap and cementing the two pieces at a different angle would give you the space you need.
    – user113627
    Jun 15, 2021 at 17:57
  • 1
    You could be on to something. If it is cast iron like my own It may very well of been wrapped with fiberglas or similar product and epoxied in place with the elbow fitted while it cured.-
    – user113627
    Jun 16, 2021 at 5:37

2 Answers 2


Can't be guaranteed but it probably will fit using your existing plumbing fittings. You have tons of space and plenty of vertical drop to the wall drain. Everything you have there is compression/slip joints that have some room to slip in and out and rotate.

The new unit is 3/4" wider so you'll rotate it and the trap to a position where they line up, then you will rotate the T coupling that joins the other sink so that it is pointing directly at the other sink and you'll couple those together. Should be enough play in all components to make it all go smoothly.

You never know though ... maybe some of those couplings have been cracked or broken or glued or otherwise abused and not reusable. You need to be prepared to run out to the store for replacement bits if you run into problems.

Don't forget the dishwasher drain hose needs to make a loop up high between the sink and the wall before coming back down to join the new disposal.

  • 1
    Good answer. With the new disposal, DRY FIT (or only loosely thread the slip joints) any connections that you glue.
    – user113627
    Jun 15, 2021 at 17:57
  • Looking at it from a different perspective: the drain exit is as low as it gets. If it won't fit here it won't fit anywhere. I suggest OP get all the fitting for a completely new install, and return what's not used.
    – P2000
    Jun 15, 2021 at 19:49
  • Re glue, the only glued parts I see are the first elbow out of the wall and an extension on one side of the trap. Neither of these limit you in any way, you can just re-use them, you should not have to glue anything. With any luck you don't even have to remove anything, just loosen all the couplings, replace the thing, realign and tighten.
    – jay613
    Jun 15, 2021 at 20:14
  • Thank you for your answer Jay. Upvoted. One of my concerns is that as the T coupling is rotated, it looks like the length of the (nearly) horizontal pipe coming from the other basin will need to be shorter or longer (depending on which direction the T coupling needs to be rotated to make things fit best). I used to work with steel quite a bit, where everything needed to be exact and there was never any wiggle room. Based on this added comment, do you think there will be sufficient wiggle room? Thanks again. Jun 16, 2021 at 3:48
  • 1
    I was concerned about that too. If the T joint moves say 1/16 inch further away is there 1/16 inch extra pipe in the coupling? You could open that T joint now to see how much extra there is. Even 1/4 inch will be plenty. If not, go buy a longer one. Alternately swivel the disposal 90 degrees clockwise (looking from above the sink). Then the cross piece will be too long and everything will definitely fit but it will eat up a little of the most convenient floor space in the cabinet. It's nicer to have the disposal exit pointing backwards.
    – jay613
    Jun 16, 2021 at 12:05

If there is no wiggle room as jay613 suggested you will have no choice but get other parts. The T is not directly centered between both sink drains because the disposal outlet is angled back. The new dispoal will offset the T regardless where you place the outlet

The horizontal pipe can be shortened or replaced with a longer one but you will have to change out the down tube and the P-trap to be able to swivel parts around. Here's a link to appropriate replacements.

looking straight down. The arc of where that disposal outlet bends down and the arc of that P-trap inlet have to intersect.

EDIT: There are offset fittings that work by shifting a pipe anywhere from 1/4" to 1 inch to the side that could be considered.

  • Thanks. Upvoted. I'm following everything you are saying except that the down tube and P-trap will have to be replaced. Can you elaborate why? Jun 16, 2021 at 12:36
  • Thanks. I am just doubtful there will be 3/4" wiggle room for pipes to reconnect with the stationary P trap cemented in place. You might be able to get the disposal to lean away from the pipes enough. The sheet metal of the sink bottom will flex a little that it isn't really noticeable,
    – user113627
    Jun 17, 2021 at 2:45
  • 1
    EDIT added as additional info.
    – user113627
    Jun 17, 2021 at 3:16
  • Thanks for your note about offset fittings. I don't think I had heard of those before. Jun 17, 2021 at 7:01

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