Bathroom Systems
The bathroom is one of the most interconnected systems in the entire CTC build.
It contains the 50‑gallon fresh water tank, multiple fixtures, and the washer/dryer combo, and it also supplies water to the kitchen.
This page documents how the bathroom’s plumbing, drainage, hot water, and electrical systems work together as a unified whole.
1. Fresh Water Supply (Cold)
The 50‑gallon fresh water tank is located inside the bathroom footprint.
This tank feeds all cold‑water fixtures in the trailer through a 12V water pump and optional accumulator tank.
- Bathroom sink
- Shower
- Washer/Dryer Combo
- Kitchen sink (cross‑room connection)
Because the tank is inside the bathroom, most plumbing runs are short and accessible.
The kitchen sink is the only long run, but it is still supplied from this same system.
2. Hot Water System
The trailer will include a dedicated hot water system.
The final heater type and location are still being planned, but the garage is the leading candidate due to its ventilation, service access, and proximity to the bathroom.
Hot water will be supplied to:
- Bathroom sink
- Shower
- Washer/Dryer Combo (if supported)
- Kitchen sink
Routing hot water lines from the garage upward into the bathroom and forward to the kitchen provides a clean, centralized layout.
3. Grey Water System (Bathroom)
All bathroom fixtures produce grey water, including the shower, sink, and washer/dryer combo.
These drains are combined into a single grey water line that flows into a small under‑floor catch tank.
- Shower drain (raised 4″ for trap and slope)
- Bathroom sink drain
- Washer/Dryer Combo drain (high‑flow discharge)
- 10–20 gallon under‑floor grey 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.
All soaps used will be biodegradable, making a combined drain system appropriate.
The grey system includes:
- Air admittance valve (AAV) for the sink
- AAV for the washer/dryer drain
- Vent line for the grey catch tank
4. Grey Water System (Kitchen)
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.
5. Toilet System
The bathroom 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.
6. Electrical Requirements
The bathroom includes both 12V and 120V electrical components.
- Washer/Dryer Combo: 120V AC, dedicated circuit
- Water Pump: 12V DC, fused line
- Lighting & Ventilation: 12V DC
- Optional: 120V GFCI outlet
7. Space & Access Planning
The bathroom layout includes the shower, toilet, sink, washer/dryer combo, and the 50‑gallon fresh tank.
The 2D view shows key dimensions such as 1′ 10″, 2′ 6″, and 6′ 7″, which define clearances and plumbing routes.
The raised shower base provides room for a shallow P‑trap and proper drain slope.
The washer/dryer and tank placement allow for clean routing of supply and drain lines.
8. System Summary
The bathroom acts as the central hub for the trailer’s water systems.
Cold water, hot water, and grey water all originate or pass through this space, and the kitchen sink is supplied from the same fresh water tank.
The complete system flow is:
- Cold Water: 50‑gal tank → pump → fixtures
- Hot Water: heater (likely in garage) → fixtures
- Grey Water: shower/sink/washer → combined drain → 10–20 gal catch tank → hose outlet
- Kitchen Grey: separate internal tank
- Toilet: self‑contained, no plumbing tie‑ins
As the build progresses, this page will expand to include the final hot water heater selection, plumbing diagrams, and installation notes.