Water proof flooring

[Mobilesport]

I'm going to redo my floors , I just laid down new vinyl flooring a while back , I'm pulling it out  so I can put new wood underneath , I'm going with some sort of 1 inch sheets , I would like to find something thats water proof and I want to glue my vinyl floor tiles down to it  ,, seal up all the edges with sealant and nice trim.
Any recommendations on what to use for waterproof sheets for the floor or should I go with what I normally use , particle board and seal it with polyurethane and then glue down my tiles.
Reason I'm putting in new floor is the 1/2 " particle board I used the first time around caved in in a couple of small spots when I walked on it , the area over the fuel pump I have a hole in the metal to access the fuel pump , didn't cave in real bad but it was flexing a little , the one inch thick will be enough that I won't need any more structual support and solve it rather easy.

 

[bigsallysmom]

perhaps something that won't expand when in contact with moisture. 20 years ago I used marine grade plywood for exterior needs. one piece of linoleum.

 

[highdesertranger]

yeah don't use particle board or OSB. I would also advise marine plywood like bigsallysmom said. 1/2 inch marine plywood is plenty. it will not fail like the particle board did. if you feel that's not enough go with 3/4 but I think that's overkill. highdesertranger

 

[DannyB1954]

One inch would be very heavy. They make vinyl flooring in many patterns that snap together like laminate flooring. Because how they interlock, I don't think water goes through very easy, (as in a spill). http://www.homedepot.com/b/Flooring...-Flooring-Resilient-Vinyl-Planks/N-5yc1vZbzjz
Sheet vinyl is the most waterproof as has been mentioned. make templates from cardboard sheets.

 

[highdesertranger]

sheet vinyl is not water proof. if exposed to water long enough water will soak though. highdesertranger

 

[BradKW]

Some of the better tile guys I know always use this RedGard Waterproofing and Crack Prevention Membrane in their showers...

 

[TrainChaser]

I wouldn't use particle board for anything!

Let some real sheet linoleum and have it go up the walls a bit.

 

[DannyB1954]

sheet vinyl is not water proof.  if exposed to water long enough water will soak though.  highdesertranger

Out of linoleum tile, carpet, and sheet vinyl, I would say that sheet vinyl is the most waterproof. What would you recommend for a van for the most water resistance?

There are different grades of sheet tile, I would go with commercial over residential. The color pattern goes all the way through on the commercial, so even if it wears a bit the pattern does not wear off.

 

[highdesertranger]

I was just pointing out, the term waterproof is not correct. if I wanted a water proof floor I would seal it with some type of 2 part resin. like what they use on surf boards or bar tops. highdesertranger

 

[Mobilesport]

I was just pointing out,  the term waterproof is not correct.  if I wanted a water proof floor I would seal it with some type of 2 part resin.  like what they use on surf boards or bar tops.  highdesertranger

This floor is coming out nice , I went with 3/4" Marine plywood , I painted all the edges gloss black , I'm going to glue down my Vinyl flooring tomorrow ( color is called smoked ember ,, kinda dark grey looking with design,  , I gotta nice hatch door for fuel pump access , real nice , will post pictures when I'm done.
Thanks for the advice on the Marine plywood , very expensive and alot of work just cutting it , all I have is a old broken jigsaw and man it took a long time , in the end it was worth it , it really finished off my interior. 
Thanks again to everyone.