So, our subfloor is almost complete! If you want to know what specific modifications we made to our trailer before starting our subfloor, check out one of our previous posts!

Today's post is broken down into 3 different parts. I've added a picture below each section to give you a better idea.

  1. Installation of Galvanized Flashing (see pic below)
Wandering on Wheels Galvanized Flashing

     2. Planing Down & Epoxying Wood Pieces (see pic below)

Wandering on Wheels Wood Epoxy

     3. Installation of Actual Floor Joists (see pic below)

Wandering on Wheels Joist Installation

Alright, so:

These were the 3 major components of putting the subfloor together. Sounds easy, right? Not so much. Huge props to my incredible husband who gives it heck every single day out there! Here's the detailed breakdown:

  1. Installation of Galvanized Flashing -   This was extremely necessary because you MUST waterproof your home. Galvanized flashing protects the undercarriage of the home and blocks all moisture from penetrating the underside of the house when it's being towed down the highway or simply sitting in a cajillion inches of snow. We had to come up with a clever way to do this though because our trailer isn't 100% flat. Unless your trailer is custom built, you will inevitably run into this same issue. More to come on th is later, but here's how we installed our galvanized flashing:
    • Acquire the flashing - We drove around to a LOT of places and were finally able to track down 26 gauge flashing. A local building supply house had it and we ended up purchasing 9 sheets of 4 foot x 10 foot sections. Here the sheets are in the back of Brian's truck!
Wandering on Wheels Brian's Truck
  • Cut the flashing - Okay, take a look at our trailer (pic below). The trailer isn't all in one plane/level, so we had to improvise. Instead, we marked each sheet and cut it with a 4 1/2" angle grinder cutting wheel. Sidenote: This process took the better part of a day and a half. We also ended up burning through multiple cutting discs. We did, however, have to overlap the pieces at some locations. Where we had to overlap flashing, we overlapped 8" with the intent to go back and tape the seams with rubber butyl flashing tape.
Wandering on Wheels Uneven Trailer

Totally different planes happening here

  • Install the flashing - Finally, it was time to actually put the flashing down. We rolled it out between each section of the trailer (see picture below). Of course, we also did the same on the bed loft (see previous post if you're confused about what the bed loft is!).
Wandering on Wheels Galvanized Flashing

2.   Planing Down & Epoxying Wood Pieces - I want to note that this isn't necessary for everyone. if you have a 100% flat trailer, this wouldn't be an issue for you. By default, if you don't have a custom trailer, chances are you're going to have to come up with a crafty way to waterproof your trailer. In pictures below, you'll see that we had to use pieces of wood to wedge in between steel members to hold our galvanized sheet metal in place. We used some crazy epoxy my Dad (another shout out Pops for giving us such a great place to build our house and some awesome resources!!!) uses on the trimmable floor joists his company manufactures to hold these pieces in place.

We purchased multiple pressure treated 2x2's and planed them down to 1 1/4" to fill the gap in between the steel flange and the steel cross members (see pic below).

Wandering on Wheels Epoxy Wood
Wandering on Wheels Epoxy Wood 2
Wandering on Wheels Epoxy Wood 3
Wandering on Wheels the epoxy

The craziesT epoxy you'll ever not want to lay your hands on.

Wait, remember how I said we were going to tape the overlapped joints with rubber butyl tape? This is what that looks like!

Wandering on Wheels Butyl Tape

And finally.....

3.  Installation of the Actual Floor Joists - We purchased lots of pressure treated 2x4's (for the bed loft) and 2x6's (for the main trailer bed). More in a bit on why we chose different sizes for each application.

  • The Bed Loft - After purchasing, we first built the entire bed loft platform frame on the ground with 2x4's. Everything was screwed in place on the ground and then forklifted into place on top of the custom modified bed loft (above the 5th wheel).
Wandering on Wheels Forklift Bed Frame
  • The Main Deck - For the main trailer deck, we purchased pressure treated 2x6s. The reason we went with 2x6s on the main deck is because we wanted to obtain a certain R-value that we could only get with a 6" deep of a cavity. We also wanted enough space to run our plumbing in the subfloor as opposed to underneath (because we will be living in a very cold climate). In the pictures, you'll see that we cripple studded our joists to make them more secure. The bed loft and the front half of the trailer can be cripple studded because there is no plumbing to run in those parts of the house. Also, we ran our joists length wise (the 35' long way) to attempt to utilize the unevenness of our trailer to our advantage. There is a big long schpill and countless hours spent on retrofitting wood to fit each nook and cranny of the uneven trailer that we won't go into :) just know - my husband is one patient guy.

We still have a small section to frame out and then we will start running plumbing. When underfloor plumbing is run, we will then fill the entire cavity with closed-cell spray foam insulation. Many more pictures and posts to come. In the meantime...

... queue some miscellaneous progress photos!

Wandering on Wheels Progress 1
Wandering on Wheels Progress 2
Wandering on Wheels Progress 3
Wandering on Wheels Progress 4
Wandering on Wheels Progress 5
Wandering on Wheels Progress 6
Wandering on Wheels Progress 7
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2015-05-20 15.56.34.jpg

Lessons Learned

  1. If we were to do it all over again, we would consider running the joists the opposite way than we actual ran them. This would have eliminated all of the notching and custom fitting we had to do.
  2. Don't get crazy epoxy on your leg hair.


  1. A miter saw, a speed square, and a solid drill are invaluable.
  2. Just like the old carpenter saying goes... when you make a cut, leave the line.

Until Next Time,

-Brian & Skyler

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