Questions about tiny house plumbing

As I continue to refine my plans and attempt to think of all problems before they arise, and am left with a few hang-ups. One being: How do I winterize my exterior plumbing? And: How should I design to reduce the need/headache for winterization, if I end up living in a climate where cold winters are a reality?

Example tiny house plumbing

Example tiny house plumbing

I’m still seeking answers to these questions, and would love your input.

One thing I am considering is to keep as much of the graywater drainage within the insulated walls, only exiting in the house in one, or maybe two spots. This is a bit complex, as I intend to include a shower, bathroom sink, kitchen sink, and combo washer/dryer unit. The two bathroom items, and the kitchen sink are all in pretty close proximity. I think I can funnel the two sinks into the shower drain (by keeping those pipes in the walls and sub-floor). But the washing machine is on the other side of the house. I don’t want to seriously compromise the insulation throughout both walls and floor by crisscrossing my already small insulatable area it with 2-inch PVC drainage pipes. I guess I need a second  exit for that.

All-in-all, I’m looking at potentially two exits through the sub-floor. Both will require p-traps under the house, as there is no space internally. If I’m dealing with freezing winter temps, I’m guessing that means one or two sets of heat tape and insulation to keep those from freezing. I also have to worry about keeping incoming fresh water un-frozen as well.

Anyone have some good electric heat-tape recommendations?

Do you have working setup that is much different than the above?

I’ve love to find out more about what others are doing with their plumbing in colder climates.

Author: Alek Lisefski