Is a p-trap necessary? I installed a garbage disposal and the outlet was lower than the drain in the wall, and didn't have sufficient room, so I installed just a straight pipe with a curve to the drain in the wall. Is this OK, or am I going to have problems? Thanks

Yes a trap is needed. The purpose is to keep sewer gas out of your house. The 'P' portion holds water, effectively sealing off the pipe.

I'm curious what you mean by a pipe with a 'curve' in it?

At any rate the real pros will be around in the morning and should be able to provide you with a solution, I have to imagine this is a fairly common problem. Best of luck.

SC-tbdf said it dead on! You need a p-trap for all fixtures.

In this case, sounds like you kind of bent the pipe over and up to join to your disposal. That is not going to keep the sewer gasses from entering the house.

Put a ptrap up to the disposal and see how the outlet of disposal and waste pipe in wall line up then... may be surprised to find that they line up properly (see pic. Below). The outlet of disposer can be lower than the wall pipe... the ptrap just won't have a long piece coming out of it, like in pic.

While purchsing the ptrap, also purchase an 1.5" desanco fitting, and an 1.5" street desanco fitting, 2-1.5" street 90s, 2-1.5" 90, 1-1.5" dandy cleanout (see pic.) and 1-1.5" coupling (some of these are in case the ptrap doesn't work somehow.. then will make your own ptrap.. ;) ).

Let us know what you do... Mark

It's difficult to improve on Marks answers but here's another hook-up to consider, (see image). Bottom line? Traps protect you from sewer gas entering your home. Sewer gas's a health hazard to your family and the methane content makes it explosive. Good luck, Tom

The last time I installed a new deep sink I ran into the same problem. The only solution was to install a S trap which is outside code. Other than this you'd need to open the wall and see if you can lower the connection to the drain line, usually a big task.

I am not able to fix this right now, I installed the sink at my girlfriends house. If she put the garbage disposal stop in the drain would that be good enough until I can get back to her house to re-plumb?

The curve is a curve that wraps horizontally around the garbage disposal. I rotated the outlet 90 degree pipe so it no longer faced downward.

Quote:

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Originally Posted by SC-tbfd

Yes a trap is needed. the purpose is to keep sewer gas out of your house. the 'P' portion holds water, effectively sealing off the pipe.

I'm curious what you mean by a pipe with a 'curve' in it?

At any rate the real pros will be around in the morning and should be able to provide you with a solution, I have to imagine this is a fairly common problem. best of luck.

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If I understand the question Paul left his girlfriend with a direct open conmection between her kitchen and the city sewer allowing sewer gas to enter her home. Sewer gas is a health hazard and the methane content makes it explosive. You have two options here. 1) Tear up the wall and lower the stub out** or** 2 )build a "S" trap; as Bob suggested in a earlier post. The one thing you can't do is ignore this situation. FIX IT!! Good luck, Tom

Reverse the trap and install it backwards. This will significantly lower the trap and you will probably have to add an extension to the elbow out of the disposal.

Review this thread for pictures of this.
https://www.askmehelpdesk.com/plumbi...ed-178738.html

I am afraid that reversing the trap doesn't fix this type of situation. I had the same situation and the actual drain opening of the disposal is lower than the lateral coming out of the wall. The water can't run up hill so consider the illegal S trap if code doesn't worry you.