moisture barrier for non-metal van floor?

[NoahForman]

So, my van has a fiberglass body that's bolted onto the cab in the front, and onto a metal frame in the rear.&nbsp; But, the floor isn't even attached to the body of the van.&nbsp; It's plywood that sits directly on top of the beams of the van's frame.&nbsp; I tore out the old floor and am going to put a new one down.&nbsp; So, I'm planning on 1/2" plywood for the base, then some type shallow wooden beams with foam boards in between them for insulation, then another layer of plywood on top of that, and probably a rug or something.&nbsp; My question is where I need to place my moisture barrier.&nbsp; I need to protect the base plywood layer from moisture coming off of the ground.&nbsp; Should I paint it?&nbsp; Coat it with fiberglass resin?&nbsp; Do I need a moisture barrier between the base plywood layer and the insulation layer?&nbsp; Then, I'm going to need a moisture barrier between the living space and the insulation layer.&nbsp; Should I put a plastic sheet in between the top plywood layer and the foam/wooden beam insulation layer?<br><br>I'm open to a better way of doing this.

 

[Ballenxj]

Hi Noah, That's an interesting sounding van. You say the wooden plywood floor is not even attached to the van sides? What was the van originally used for? Can you post pictures of both the van, and the seams between van sides &amp; floor? <br>Right now I'm thinking a good coat of Rhino Liner over one inch marine plywood, and a nice fat bead of silicone between floor and sides. <br>-Bruce

 

[NoahForman]

I can get a real picture later, but this is the same type of van I have:<br><br>http://www.smartcarguide.com/listimg/img1_0213/27/img_10582983_00.jpg<br><br>It's a Ford E350 with a Unicell Aerocell SRW fiberglass body.&nbsp; I've already torn the floor out, so you can't see the seam between it and the sides.&nbsp; But, it was just plywood, sitting right on top of the van's chassis, that butted right up against the van sides.&nbsp; Whoever installed the body might have added some metal beams in order to raise the floor above the wheels.&nbsp; I'm not sure what's stock and what was added.&nbsp; Actually, there was a piece of fiberglass glued to the van sides, perpendicular to the sides, which ran the length of the body, and sat right above the floor.&nbsp; The floor was puttied on to this piece, in some places.&nbsp; I cut it off because I thought it would interfere with my walls and wall insulation. &nbsp; &nbsp;

 

[James AKA Lynx]

A lot of Travel Trailers fiberglass encase the plywood. <br><br>James AKA Lynx

 

[Ballenxj]

It looks good, but I'm not familiar with that sort of installation. I'm sure you can improve upon that. <br>-Bruce

 

[James AKA Lynx]

As I recall, both Shasta and Egg Camper makes and installs fiberglass reinforced plywood flooring. Check the Fiberglass RV forum for instructions. It has been several years and things do change.<br><br>James AKA Lynx

 

[Lostinspace]

So the fiberglass shell wasn't tied into the floor? Seems to me you woud want it tied together to give some strength.

How is the shell mounted to the frame? Maybe they didn't tie the two together to prevent stress cracks from vibration and flex of the framing.

I had a "Love bug" back in the 70's. Its just like a casita and the floor wasn't tied to the body either as I remember.

 

[highdesertranger]

ok some good advice already posted&nbsp;here.&nbsp; I to am curious to know&nbsp;how the fiberglass body is attached.&nbsp; as far as the floor goes for your base I feel you need more than 1/2 inch plywood.&nbsp; sealing with fiberglass or just glass is a great idea and provides a vapor barrier.&nbsp; not sure if you need another vapor barrier I want to see what others say.&nbsp; highdesertranger

 

[Lostinspace]

The floor on the love bug,as I remember, was just 3/4" plywood with a lynoliun (sp?) floor covering. Wasn't real warm in the winter, not that we used it in the winter much. I think the underside was just painted, not fiberglassed.

 

[Zil]

I had an early VW van, had a metal floor. <br>The lip you removed shouldn't had been.<br>You need to make something to tie the floor to the sides.