Floor Building Question

[chorizon]

I built a frame under my floor so that I could have something for my walls to screw into. I suppose I could have done it differently, though.

You are doing some nice fabrication there on your trailer. I had a look. Have you added a water tank and pump?

Thanks! I did add a Valterra 9 gallon tank, with an overkill Shur-flo demand pump.

[StandUpGuy]

3/4 inch ply can be built going past ( cantilevered ) the frame. Not sure how far I would have to do some eye ball engineering but just setting here 8 inches does not seem out of the question unless you build side walls from brick. You would then be on your own. I built my floor of 3/4 inch on spars past my frame. It is way way over built and added a lot of time, weight, height and cost that just was not needed. or will be used again. Even a good 1/2 inch ply can be cantilevered some and will be plenty for the floor of a TD. Heck, if the ply is not cantilevered past the frame I believe 3/8 of good quality ply would work with a few frame cross members for it to rest on. Which most trailers will have.

Randy

Thanks that is good to know. I was planning on luan inside and luan outside with a 3/4" insulation glued in the middle. It should be pretty light. I am glad to get your imput as I do not want over or under build.

[dh]

Yep, you can cantalever 1/2'' ply about 8'' no problem, my waterbad is built like that, the dresser base has 1/2'' OSB sitting on top of it, overhanging at least 8'' on all sides, the 1 1/4'' thick oak sides are attached to the OSB with L brackets, which also support the heavy head board/cabinet.

[StandUpGuy]

Yep, you can cantalever 1/2'' ply about 8'' no problem, my waterbad is built like that, the dresser base has 1/2'' OSB sitting on top of it, overhanging at least 8'' on all sides, the 1 1/4'' thick oak sides are attached to the OSB with L brackets, which also support the heavy head board/cabinet.

1 x 3 is light. I thought I would do some framming with it below the floor and use it to tie into the side walls.


By justoneman at 2011-04-12

Infact maybe even 3/8" plywood for the floor!

[Artificer]

My first trailer used the 2x2 steel box tube as the floor frame. A cleat was glued/screwed to the floor's 1/2" plywood, and had tee-nuts on the top edge. I could then bolt from the bottom of the 2x2 up into the cleat. The cleat was also used as an attach point for the walls. I've hung the trailer from the crane to make fiberglassing the bottom easier. No structural problems at all. The trailer was designed for off-road use.

If you're making the sides 1 sheet high (48"), this gets the most height. Subtract the thickness of the ceiling, and that's your interior height. The only problem is covering the plywood edge, and the seam with the frame. Either more fiberglass, or a trim piece, and you're done.

Michael

Note: the image in the attachment sticky is a bit wrong for my trailer. The floor sheeting is directly on top of the steel frame. The frame is infilled with 2" of foam, and the bottom was fiberglassed for protection from road debris.

[bobhenry]

1 x 3 is light. I thought I would do some framming with it below the floor and use it to tie into the side walls.


By justoneman at 2011-04-12

Infact maybe even 3/8" plywood for the floor!

Remember that 8" cantaliver is carrying the weight of the walls and roof.
It is also absorbing any impact loads that are thrown at it. I like your thinking in this drawing and if some short blocking was added perpendicular to the two 1x3's shown in the drawing you have essentially triangulated the support. The down side to extendiny your outer sheathing below the floor is you are reducing your head height inside by about 4".

My 5x10 teardrop was built almost as shown in your pic and I stood my sheets up to get my 5' + head height

[StandUpGuy]

1 x 3 is light. I thought I would do some framming with it below the floor and use it to tie into the side walls.


By justoneman at 2011-04-12

Infact maybe even 3/8" plywood for the floor!

Remember that 8" cantaliver is carrying the weight of the walls and roof.
It is also absorbing any impact loads that are thrown at it. I like your thinking in this drawing and if some short blocking was added perpendicular to the two 1x3's shown in the drawing you have essentially triangulated the support. The down side to extendiny your outer sheathing below the floor is you are reducing your head height inside by about 4".

My 5x10 teardrop was built almost as shown in your pic and I stood my sheets up to get my 5' + head height

The limitation of my ceiling height is by the top of my garage door opening and how low my actual floor is. Since I am placing no wood framing between my plywood decking and the metal trailer frame, I have the most headroom possible.

I of course will be seaming the walls beyond the 48" width of material.

[GPW]

How about just a few metal braces ... bolt em up ..

[StandUpGuy]

That would certainly support the overhang. Not sure how economical it is.

[GPW]

You wouldn't need that many ...

[CARS]

That would certainly support the overhang. Not sure how economical it is.

I wouldn't doubt that a few shelf brackets would do the job of extra support for very little money.

[GPW]

Cars ...