Cargo Trailer Under‑Floor Insulation – Another Great Reference Video
This video is another strong example of insulating a cargo trailer from the bottom
instead of building up the interior floor. It reinforces the method I plan to use for my own CTC build,
since it preserves interior height, reduces thermal bridging, and allows for thicker insulation without
sacrificing living space.
The builder shows a clean, efficient method for insulating the underside of a cargo trailer.
This approach is ideal for anyone who wants maximum interior height and a well‑sealed,
thermally efficient floor system.
Cleaning and prepping the underside before installation
Installing rigid foam board between the steel frame rails
Using spray foam to seal edges and prevent air infiltration
Supporting the insulation with straps, sheathing, or underbelly material
Protecting the foam from road debris, moisture, and long‑term wear
Tips for working overhead safely and efficiently
📝 Why This Method Works Well
This video reinforces the same advantages shown in other under‑floor insulation builds.
It’s a practical, real‑world demonstration of why insulating from the bottom is often the
best choice for cargo trailer conversions.
No interior height loss — the biggest advantage for my build
Allows thicker insulation than interior floor framing
Better thermal break from the steel frame
Cleaner interior layout with no raised floor
Improved energy efficiency for heating and cooling
More usable interior volume for cabinetry, appliances, and living space
This video provides another clear example of how to insulate a cargo trailer floor from underneath.
It confirms that this method is practical, durable, and ideal for maintaining maximum interior height
in a CTC build. It’s a valuable reference as I plan my own under‑floor insulation strategy.
This video demonstrates a floor insulation method that I prefer for my own CTC build.
Instead of installing insulation inside the trailer—where it reduces interior height—
the builder installs all insulation under the trailer.
This approach preserves headroom, allows for thicker insulation, and keeps the interior floor
structure simpler and cleaner.
The builder walks through the entire process of insulating the trailer floor from the underside.
This method is ideal for anyone who wants to maximize interior height while still achieving
strong thermal performance.
Cleaning and prepping the underside — removing debris and checking for rust
Installing rigid foam board between the frame rails
Sealing gaps with spray foam to prevent air infiltration
Protecting insulation with underbelly material or sheathing
Moisture and road‑spray considerations for long‑term durability
How to support insulation so it stays secure while towing
📝 Why I Prefer This Method for My Build
No loss of interior height — keeps the finished ceiling at maximum height
Allows thicker insulation than interior floor build‑ups
Cleaner interior layout — no need for raised floors or step‑ups
Better thermal break from the metal frame
Reduces thermal bridging through the steel floor crossmembers
More efficient use of space — insulation lives outside the living area
🔧 Materials & Techniques Highlighted
Rigid foam board (various thicknesses)
Spray foam for sealing edges and gaps
Underbelly sheathing or protective panels
Adhesives and mechanical fasteners for securing insulation
Floor insulation is one of the most important decisions in a cargo trailer conversion.
This video provides a clear, practical example of how to insulate the floor from underneath,
which is the method I plan to use for my own build. It preserves interior height, improves
thermal performance, and keeps the interior layout simple and efficient.
As part of the electrical planning for my cargo trailer conversion, this video was a solid reference for
wiring a dedicated branch circuit for the 12V water pump. It walks through layout, protection, and clean routing.
While planning the plumbing for my cargo trailer conversion, I found this video really helpful for understanding
how flexible RV plumbing should be laid out and supported. It lines up well with the direction I’m taking on my build.
Hot Water Heater Bypass Valve — A Small Upgrade With Big Benefits
One of the smartest additions you can make to any RV or cargo‑conversion plumbing system is a hot water heater bypass valve. I recently watched a great walkthrough on how these valves work,
and it reinforced why this little setup is worth including in any build—especially one designed
for year‑round use.
What a Bypass Valve Does
A bypass valve gives you full control over whether water flows into the hot water heater or around it. That flexibility matters for two major reasons:
1. Winterization Made Easy
When it’s time to winterize, you don’t want gallons of antifreeze filling your hot water tank.
A bypass valve lets you isolate the heater so antifreeze only travels through the lines—not the tank—
saving time, money, and cleanup.
2. System Flexibility & Maintenance
If you ever need to service, replace, or temporarily disable your water heater, the bypass lets you
keep the rest of your plumbing system fully operational. Cold water continues flowing to your fixtures
while the heater stays offline.
How It Works
A typical bypass setup uses two shutoff valves and a short crossover line:
Valve A: Stops cold water from entering the heater
Valve B: Stops hot water from exiting the heater
Crossover Line: Connects cold to hot so the system stays pressurized and functional
Turn two valves, and the entire heater is isolated. Simple, clean, and reliable.
Why I’m Including It in My Build
My plumbing system is designed for serviceability and future upgrades, and the bypass valve fits
perfectly into that philosophy. It supports:
Easy winterization
Quick maintenance
Future heater swaps (gas or electric)
Cleaner plumbing architecture
It’s a small detail that pays off every single year.
Tank vs. Tankless RV Water Heaters for a Cargo Trailer Conversion
Plumbing Systems Planning Hot Water
As I plan the plumbing and hot water strategy for my cargo trailer conversion, I’ve been digging into the
real-world differences between traditionaltank-style RV water heaters and tankless/on-demand units. A recent video, “Tank Vs Tankless RV Water Heaters”,
pulled together a lot of practical experience from RV owners, and this post captures the key points
and how they apply to my build.
1. Hot Water Delivery and User Experience
Tank-style heaters store and pre-heat a fixed volume of water, so hot water is available
almost immediately at the faucet. You open the tap, and you’re essentially drawing from a pre-heated reservoir.
Tankless heaters work differently: they need a minimum flow to trigger the burner, then ramp up
to temperature. That means a delay before hot water arrives, and some variability as the system stabilizes.
Certain premium models (like the Truma AquaGo) offer a “comfort” or recirculation mode to keep water warm
in the lines, but that comes with additional energy use.
2. Water Usage and Conservation
One of the big tradeoffs with tankless systems is water waste during warm-up. Until the heater
reaches the target temperature and pushes that hot water all the way to the fixture, you’re sending usable water
down the drain. For anyone with limited gray tank capacity, that’s not trivial.
With a tank heater, the water is already hot and more predictable, so it’s easier to mix hot and
cold at the faucet and get to a comfortable temperature quickly. That can translate into less fiddling and less
waste overall.
3. Fuel, Power, and Flexibility
A common selling point for tankless heaters is efficiency: they only fire when water is flowing.
Many RV owners report lower propane usage after switching to tankless, especially if they take longer showers.
Tank heaters, on the other hand, often support multiple modes—propane, electric, or both.
That flexibility matters at campgrounds where shore power is available: you can save propane by running on
electric, or use both for faster recovery when demand is high.
4. Winter Performance and Cold-Weather Behavior
Cold weather exposes some of the weaknesses of tankless systems. They can be more sensitive to:
Low incoming water temperatures
Low water pressure or marginal pumps
Temperature rise limits across the heat exchanger
Owners in colder climates sometimes add insulation, small heaters, or circulation loops to keep lines from
freezing and to stabilize performance. By contrast, tank heaters tend to be more predictable
in winter, as the entire tank is kept at temperature and the system is generally simpler.
5. Installation, Tuning, and Reliability
Tankless units are more “tunable” but also more finicky. They care about:
Water pressure: too low and they may not fire consistently.
Flow rate: fixtures with very low-flow aerators can cause cycling.
Temperature rise: large jumps from cold inlet to hot outlet push the unit harder.
Tank heaters are mechanically simpler and often more forgiving. While both types can be reliable
when installed correctly, the tank-style design has fewer variables to tune and fewer edge cases to manage.
6. Real-World Experiences from RV Owners
The comments and user experiences around this topic are split, but informative:
Pro-tankless: Full-timers love the “endless shower” experience and reduced propane usage.
Back-to-tank: Some owners reverted to tank heaters after frustration with cold-weather
performance or water waste.
Hybrid setups: Others run creative combinations—small under-sink electric heaters,
recirculation loops, or dual-mode tank heaters—to get the best of both worlds.
How This Informs My Trailer Build
For my cargo trailer conversion, the decision isn’t just “tank vs. tankless”—it’s about how the entire
hot water system interacts with gray tank capacity, winter use, and fixture layout.
Endless hot water is appealing, but the delay and extra water down the drain are real
concerns with a finite gray tank.
Cold-weather reliability matters, especially if the trailer sees shoulder-season or
winter trips.
A hybrid approach—for example, a traditional tank heater combined with a small
point-of-use electric heater near the shower or sink—could minimize wait time and water waste.
Heater placement relative to fixtures will be critical. Shorter runs mean less delay,
less wasted water, and a better overall experience regardless of heater type.
I’m leaning toward a solution that prioritizes predictability, water conservation, and serviceability,
even if that means giving up the “infinite” hot water promise of a pure tankless setup.
Cargo Trailer Conversion – Waste Water Drain Tips (Reference)
This page documents helpful waste‑water plumbing tips from the video “Cargo Trailer Conversion Waste Water Drain Tips. Uniseal. Waste Water Tanks. RV Sewer Adapters.”
by I Ride Tiny House Adventures. I’m saving these notes as a reference for my own plumbing system design.
1. Using Uniseals for Tank Penetrations
The video highlights how effective Uniseals are for creating watertight penetrations in plastic waste tanks.
They allow pipes to pass through the tank wall without needing threaded bulkheads, and they flex with tank movement.
Key points:
Use a —cheap ones can cut oversized holes and cause leaks.
Lubricate the pipe and seal to avoid tearing the rubber during installation.
Uniseals work well for both grey and black water tanks.
2. Preventing Leaks at Fittings
One commenter recommended applying a small amount of grease on the gasket before tightening fittings.
This helps the gasket compress smoothly instead of dragging and tearing.
This is especially useful when installing:
Threaded adapters
Tank outlet fittings
RV sewer connectors
3. RV Sewer Adapters & Drain Options
The video shows how to adapt from smaller drain lines (1.5″) up to standard RV sewer sizes (3″).
This is helpful when combining shower, sink, or sump‑pump outputs into a larger drain system.
Tips mentioned:
Offset fittings can help align pipes when tank ports aren’t perfectly positioned.
Some builders downsize to a garden hose adapter for slow but simple grey‑water draining.
Always use high‑quality PVC fittings to avoid cracking under vibration.
4. Waste Tank Selection & Installation Notes
Viewers in the comments mentioned using 36–55 gallon tanks and pairing them with shower sump pumps for interior plumbing.
This aligns with my own plan to keep all tanks inside the trailer for freeze protection.
General reminders:
Verify tank wall thickness before choosing Uniseal sizes.
Support tanks fully—don’t rely on fittings to carry weight.
Plan drain locations early to avoid conflicts with framing.
5. Safety & Practical Tips
Use flush‑cut zip‑tie cutters to avoid sharp edges that can cut your hands.
Keep spare fittings and caps for emergency repairs.
Label drain lines during installation for easier troubleshooting later.
Why This Video Is Useful for My Build
This video provides practical, real‑world examples of how to handle waste‑water plumbing in a cargo trailer conversion.
The tips on Uniseals, gasket sealing, and sewer adapters will directly influence how I design my grey‑water system, sump‑pump connections, and tank penetrations.
This page will serve as an ongoing reference as I finalize my plumbing layout.
Reference: EcoFlow Delta Pro Transfer Switch Installation for Boondocking
This post documents key takeaways from the video “Best EcoFlow Delta Pro Setup for Boondocking – Install a Transfer Switch!”.
The creator demonstrates how to integrate an EcoFlow Delta Pro into an RV electrical system using an automatic transfer switch (ATS), allowing the power station to safely power all onboard circuits while remaining protected inside a storage compartment.
This installation method is relevant to my electrical planning, especially as I evaluate the EcoFlow DELTA Pro 3, the Smart Generator 4000, and a 50‑amp shore power inlet for the cargo trailer conversion.
Overview of the Setup
The video shows how the installer wires an ATS into the RV’s existing shore‑power line so the EcoFlow Delta Pro can power the entire RV without running an external cord. The Delta Pro remains inside a storage compartment, protected from weather and theft. The ATS automatically switches between:
Shore power
EcoFlow Delta Pro
Generator input
This allows all interior outlets and circuits to remain live regardless of the power source. The EcoFlow can also recharge from shore power through the same wiring path.
Key Details from the Installation
Shore power line is cut and routed into the transfer switch, then back out to the RV’s breaker panel.
EcoFlow Delta Pro output is connected to the second input of the ATS.
Generator plug is connected to the third input.
The Delta Pro remains inside a storage compartment, protected from weather and theft.
The system allows the RV to recharge the Delta Pro from shore power without moving the unit.
Safety Considerations Mentioned
Several comments and responses highlight important safety notes:
Ventilation: The storage compartment in the video has ~15 sq in of airflow, preventing overheating. The Delta Pro’s BMS will throttle or shut down if temperatures rise too high.
Aluminum-to-copper wiring: When joining dissimilar metals, an anti‑oxidant compound should be used to prevent oxidation and fire risk.
Breaker management: Some RVs require turning off the onboard battery charger to avoid unnecessary load on the power station.
Why This Setup Is Useful for My Build
This installation method aligns well with my electrical system goals:
Keep the EcoFlow unit inside the trailer for protection.
Use a transfer switch to safely manage shore, generator, and battery power.
Allow the EcoFlow to power all circuits without external cords.
Enable automatic charging from shore power.
Maintain a clean, modular, serviceable electrical system.
This video serves as a practical reference for integrating the EcoFlow ecosystem into the cargo trailer conversion, especially as I evaluate the DELTA Pro 3, the Smart Generator 4000, and a 50‑amp shore power inlet.
Notes for Future Planning
Determine ATS size and compatibility for a 50‑amp shore power inlet.
Evaluate ventilation requirements for the EcoFlow storage compartment.
Save a Drop P3 Water Flow Meter – Fresh Water Fill Monitoring
As part of planning the fresh water system for this cargo trailer conversion, I wanted a simple way to monitor how much water is going into the tanks during fills.
A small inline flow meter on the hose is an easy, low‑tech way to track gallons used and avoid overfilling.
The Save a Drop P3 is a compact, inline water flow meter that attaches to a standard garden hose.
It measures the total volume of water passing through and displays usage in gallons, making it useful for
filling RV or trailer fresh water tanks, portable containers, or even just tracking water consumption.
Type: Inline water flow meter
Connection: Standard garden hose
Display: Digital readout of gallons used
Use Case: Monitoring tank fills and conserving water
Why This Is Useful for the Build
When filling fresh water tanks, it’s easy to lose track of how much water has gone in—especially when filling from
portable containers or non‑metered sources.
A small flow meter like this provides:
Overfill awareness: Know how many gallons have gone into the tank before it reaches capacity.
Repeatable fills: Easy to track partial fills (e.g., “add 10 gallons” instead of “fill until it overflows”).
Water usage insight: Helps understand how quickly water is consumed during trips.
Portable and flexible: Can be used on any hose, not permanently installed.
How It Fits Into the Fresh Water Workflow
In practice, this meter would be attached inline on the hose used to fill the fresh water tank(s).
Before starting a fill, the meter can be reset to zero, and the display will show the total gallons added during that session.
Attach meter between spigot and hose, or hose and tank fill.
Reset meter before each fill.
Monitor gallons as the tank fills to avoid overfilling.
Optionally log usage to better understand daily water consumption.
This page serves as a reference for a simple, portable tool that can make tank filling more controlled and predictable,
especially when working with multiple tanks or off‑grid water sources.
