Proposed wall attachment option

[Lucky53s]

I'm starting to think about how I actually want to build my TD instead of just thinking about features. I have read through the wall attachment options but there are not many dimensions and details so I wanted to ask if this setup would be strong enough. If not, what changes would need to be made to strengthen it. I have my doubts, but maybe I'm just trying to over-engineer my walls. I chose this mounting option because it retains the most height from a 4 foot tall piece of plywood and I think it will look very clean.



I'm looking at doing the internal cleat with woody trim. My floor will not be in line with my frame though, I am going to hang it over at least 6 inches in order to get 5 feet out of a 4 foot trailer. My floor will be two pieces of plywood with a 2x4 in the middle so I don't have wheel wells on the inside. Here is a very rough sketch in paint (not to scale):



You can see the plywood and 2x4 frame (black and red), 3/4 ply side (light blue), 1/8 interior and 1/4 exterior Birch (green), internal cleat (maroon) and trim (grey). The arrows are screws.

I was thinking that some type of adhesive should be used in the cleat/recess area. Here are a few questions about strength though:
1. Are screws through 1/8 and 1/4 Birch enough to hold the wall on?
2. Should the trim (grey) go high enough for the top screw to hit the plywood (light blue) instead of Birch and internal cleat?

I've looked through a ton of build journals and most people just throw the walls on and show a picture but don't show how they are attached. I'm trying to avoid brackets or bracing inside for a cleaner look.

Could always go with Rabbet or Lap joint and skip the trim if what I'm thinking about is unstable, much harder, or just too much work for no good reason. Thanks for the input.

(All measurements are proposed at this point and will be determined once I get the right trailer)

[bobhenry]

I tossed down the plywood and had built a halo of 2x4 around the outside perimeter. It was glued and screwed to the underside of the plywood. When I built my walls a 1x4 was added at the bottom of the wall for the wall to set on the floor and absorbing the shock load of bumps and such. The inner ply stopped at the floor while the outer ply extended over the 2x4 so it could be glued and screwed also. I know , I know clear as mud. Here are a few pics there are more way back in my album. ( way way back)









a 5'6" wide 10' long trailer on a modified 4x8 HF trailer

[Lucky53s]

Thanks Bob. Looks similar to the Rabbet but the inner (your 1x4) doesn't run all the way up.

I'll see if I can find some time to go through your gallery for details. I'm thinking of doing similar to you but running 2x4s across each trailer cross member with 1x4s from front to back to save some weight but give support to the floor.

[Campin' Texan]

Here's what I did. I stood my 3/4 plywood walls on top of the trailer frame and screwed them into a wooden frame work that was under my flooring. The trailer supports the weight of the walls, not the screws. The black is the metal trailer. The yellow is a wood 2"x2" frame. The redish color is 3/4 plywood floor. The brown is the 3/4 plywood wall. I ran a bolt through the floor, wood frame, and trailer. The walls are screwed in from the outside. No bolts or screws show on the inside or out. It's a very clean and sturdy design.

[Lucky53s]

Here's what I did. I stood my 3/4 plywood walls on top of the trailer frame and screwed them into a wooden frame work that was under my flooring. The trailer supports the weight of the walls, not the screws. The black is the metal trailer. The yellow is a wood 2"x2" frame. The redish color is 3/4 plywood floor. The brown is the 3/4 plywood wall. I ran a bolt through the floor, wood frame, and trailer. The walls are screwed in from the outside. No bolts or screws show on the inside or out. It's a very clean and sturdy design.

That won't work for me because I'm going to hang my floor 6-8 inches over the edge of the frame to cover the wheels and widen my trailer enough for a full size mattress at least. I will have to screw right down to the wood that I install.

Just checked out your build, very nice. I'm hoping mine comes out half as nice when I'm done.

[Campin' Texan]

Gottcha. Good luck and thanks for the compliment!