After our consult with Steve I drew up some mock plumbing drawings of how the drain lines would fit together and incorporate a Waterless Ptrap. Ptraps are devices that stop plumbing gases from leaking out a sink or tub drain. I was a little obsessed about using this type of ptrap because it would fit the drain lines within the clearances of our 2”X6” floor while helping to avoid freezing in the winter.
First I used our building plans and did some math. I redrew the tub drain location because our tub and trailer are different than the plans.
I attempted to install according to my drawing but found the slope of the pipe would require that I drill holes in the lower 1/3 of our joist. Doing this will compromise the integrity of our floor framing.
Plan B: this is when we raised the tub to allow enough slope while fitting our Schedule 40 1 1/4” drain lines in the floor joists safely. Staying in the middle 1/3 of a joist is a building code thing you may read about if you like.
With all the holes drilled in our joist at the right slope I was then cutting pipe and dry fitting it with all necessary fittings, and cleaning cut ends to test the full assembly and double check the slope before gluing it all. I then moved on to priming and gluing where required, and adding pipe insulation.
Whoops...I didn't test the lines before insulating around the pipes. In lieu of testing prior to insulating, I plugged the end that will empty into our gray water tank and filled the pipes with water. The same amount of water came out after unplugging the pipe a couple of hours later so it should be good. Should is a dirty word. Fingers crossed for non-leaky drain lines.