Thanks in advance for your assistance! So I've never installed an RV style toilet, and I can see that when you push the pedal it's a straight shot down the drain, and I don't know if it holds water in there until it's flushed like a standard house toilet. Do I need to install a ptrap under the floor for it, because I'm thinking that it doesn't possess the 'ptrap effect' that a house toilet does. Help!

  • 2
    I’m voting to close this question because this is not a DIY project, but a contractor doing work for a client.
    – FreeMan
    Commented Jan 31 at 21:03

1 Answer 1


No, an RV toilet does not use a trap. The valve in the bottom of its bowl serves the same purpose (that of blocking sewer odors from rising up out of the waste plumbing/tank).

Note, however, that you need to be using the right kind of toilet. If your tiny house is a glam RV -- it's mobile and waste from the toilet will drop directly into a holding tank -- then an RV-type toilet is appropriate. On the other hand, if this is just a very small building but it is connected to municipal or private sewer, or to a septic system, then a flush-type toilet should be used. I would expect the volume of water used in an RV toilet may be inadequate to move solid waste through a plumbing system properly.

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