Floor to Trailer assembly question.

[shanna7]

We are using 1/2" Marine Ply for our floor, and planned to attach it to top of the trailer, flip it over, put XPS insulation inside the trailer framing members, then coat the bottom with truck bed liner or asphalt emulsion (something tough that won't eat the XPS). See my rough drawing.

1. I think it would be best if we sealed the bottom of the marine ply before attaching to the trailer. Overkill or no? Should we use the same undercoating material, or a paint sealant like Killz?

2. Is it okay to put XPS insulation in the trailer framing members? I know you shouldn't do it with wood because of the chance of rot in unseen gaps. We want to use this method to help save weight without foregoing floor insulation altogether. If not, what other methods have people used other than no insulation or an insulated sandwich floor?

3. We welded our Northern tool trailer frame together, and coated the welds in Rustoleum, is there any other surface prep you'd recommend, such as a few more coats of paint, etc.? Should just cover the whole shebang in the undercoating?

Any other feedback is appreciated!

[steve cowan]

I had a piece of 3/4 inch foam left so I just layed it on the floor before mattress put down.Easy.

Steve

[halfdome, Danny]

I guess it depends on how much work you're willing to do and what weather extremes you'll encounter.

I build a 3/4" plywood floor and bolt it down to the chassis much like your drawing shows.
I put a full continuous sheet of plastic laminate (plam) on the underside of the plywood before mounting it to the chassis.
The plam is a cleaner way to coat the underside and it's water proof.
I then cover the top side in the same manner after all the bolt holes are filled to balance out the sheet.
It makes for a clean looking floor that can be wiped up as easy as any kitchen counter top of the same material.

If we feel we need insulation then I have two 1/2" thick, equal sized pieces of foam insulation, each half = the size of the floor, that I can slide under the mattress, it works quite well for us.
I duct tape the raw edges to keep it from crumbling all over the place.
Danny

[shanna7]

We have these amazing manually adjustable bed frames (Pragma bed) that will be sitting on the floor, so we can't do internal insulation, otherwise that would be a great idea.

[shanna7]

In case anyone else is interested, we just took the legs off these: http://pragmabed.com/simple-adjust-hf.

[halfdome, Danny]

Never seen that before.
Our bed is adjustable by raising the tongue wheel, the K.I.S.S. factor.
Danny

[shanna7]

Chalk it up to things people who live in rainy regions think of. It was an interesting alternative to making a diner style teardrop: the perfect place to watch a movie or read a book while waiting out the rain.