Bathroom Plumbing Master Plan
This Plumbing Master Plan outlines how fresh water, hot water, and grey water move through the entire CTC build.
The bathroom serves as the central hub for the water system, housing the 50‑gallon fresh tank and multiple fixtures,
while the kitchen and garage integrate into the overall plumbing layout.
This page documents the complete system architecture, routing strategy, and component relationships.
1. System Overview
The trailer’s plumbing system consists of three major subsystems:
- Fresh Water System – cold water supply from the 50‑gallon tank
- Hot Water System – dedicated heater (location planned for the garage)
- Grey Water System – bathroom grey water catch tank and separate kitchen grey tank
The toilet is a self‑contained composting unit and does not connect to the plumbing system.
2. Fresh Water System (Cold)
The 50‑gallon fresh water tank is located inside the bathroom footprint.
A 12V water pump supplies cold water to all fixtures in the trailer.
An optional accumulator tank may be added to reduce pump cycling and improve flow stability.
Cold Water Feeds:
- Bathroom sink
- Shower
- Washer/Dryer Combo
- Kitchen sink (cross‑room connection)
PEX cold‑water lines run from the tank to each fixture, with the kitchen sink being the only long-distance run.
3. Hot Water System
The trailer will include a dedicated hot water system.
The final heater type is still being selected, but the garage is the preferred installation location due to ventilation, service access, and proximity to the bathroom.
Hot Water Feeds:
- Bathroom sink
- Shower
- Washer/Dryer Combo (if supported)
- Kitchen sink
Hot water lines will run upward from the garage into the bathroom and forward to the kitchen, creating a clean and centralized routing path.
4. Bathroom Grey Water System
All bathroom fixtures drain into a combined grey water line that flows into a small under‑floor catch tank.
This tank is not intended for long‑term storage; it acts as a buffer before grey water is discharged through a hose when the trailer is stationary or at a campsite.
Bathroom Grey Water Sources:
- Shower (raised 4″ for trap and slope)
- Bathroom sink
- Washer/Dryer Combo (high‑flow discharge)
Grey Water Components:
- 10–20 gallon under‑floor grey catch tank
- Air admittance valve (AAV) for sink
- AAV for washer/dryer drain
- Vent line for grey tank
All bathroom grey water → combined drain → catch tank → hose outlet.
5. Kitchen Grey Water System
The kitchen sink uses its own internal grey tank and is not connected to the bathroom grey system.
This keeps the plumbing simpler and avoids long drain runs across the trailer.
The kitchen grey tank is used for quick rinsing when not at a campsite, while the bathroom grey system is used only when stationary.
6. Toilet System
The trailer uses a self‑contained composting toilet, eliminating the need for a black tank or black plumbing.
- No black tank
- No flush water lines
- No roof vent stack
- Only a small 12V fan and vent hose
This greatly simplifies the plumbing layout and reduces maintenance.
7. Plumbing Routing Strategy
The plumbing layout is designed for simplicity, serviceability, and freeze protection.
The bathroom acts as the central hub, with short runs to most fixtures and a single long run to the kitchen.
Routing Highlights:
- Cold water lines originate at the 50‑gal tank
- Hot water lines originate in the garage
- PEX lines run through interior walls and protected spaces
- Bathroom grey drains slope downward to the under‑floor tank
- Kitchen grey drains directly into its own internal tank
8. Electrical Integration
Several plumbing components require electrical support:
- Water Pump: 12V DC, fused line
- Washer/Dryer Combo: 120V AC, dedicated circuit
- Hot Water Heater: 12V, 120V, or propane depending on model
- Lighting & Ventilation: 12V DC
9. System Summary
The plumbing system is designed around a centralized fresh water tank, a garage‑mounted hot water heater,
and a dual grey water strategy that separates kitchen and bathroom waste.
The bathroom serves as the core of the system, supplying water to the kitchen and managing the majority of grey water.
- Cold Water: 50‑gal tank → pump → fixtures
- Hot Water: heater (garage) → fixtures
- Bathroom Grey: combined drain → 10–20 gal catch tank → hose outlet
- Kitchen Grey: internal tank → separate system
- Toilet: self‑contained, no plumbing tie‑ins
This master plan will evolve as final components are selected and installation begins.
Future updates will include diagrams, routing maps, and installation notes.