Plumbing question

[JayLikesBus]

So I’ve got the bus completely demoed. And eventually I want to do plumbing for a small bath/ shower, sinks, etc. Was wondering when I should start the plumbing? Is it a good idea to start before sub flooring or after? What have you guys done?

[BarnYardCamp]

My sub floor = 3/4 plywood over 3/4 foam board went down first.
Used a hole saw to cut where pipes and such had to go.
Much easier than trying to fit the floor around pipes that were already installed.
Plus, there's a fair chance that in the course of your build, something will cause you to altar your plans...has happened to many of us.

[JayLikesBus]

This makes sense. After I posted this I thought of the horror of cutting around the pipes. Thanks!!

[turf]

i'd agree.

my waste tank was the first fixture I installed after the floor. i chose an rv toilet and built the rest of the build around the location of the waste plumbing constraints.

[Rucker]

Originally Posted by turf

i'd agree.

my waste tank was the first fixture I installed after the floor. i chose an rv toilet and built the rest of the build around the location of the waste plumbing constraints.

This is the best practice. Locate your waste tanks first, based on where you want that shower to be.

Look up Hepvo self sealing waste valves and see if that works better than a regular trap given your setup.

Normal drains are slanted 1/4" per foot. I think we all recommend something steeper when the drain is transverse in the bus (side to side instead of in line with the bus), so if you're parked where the bus is tilted it will still drain. I did 1/2" per foot for those.

Share pictures of your proposed design.