What adhesive to bond new floor together

[Markyt1980]

Hi there I was just wondering if anyone knows or has tips and links to adhesives best used to make a new floor of marine ply styrofoam and more ply sandwich. With Barton's around the sides. I'm having to cut away a large section at the back of Florence my first caravan and project. Any advice and tips appreciated. Also any tips for getting off the dreaded wallboard as I'm stripping her back and it's a nightmare trying to get the wall board off to acces the rotten bits

 

[Sproket]

Take plenty of photos with a tape measure sat there as a reference for when you start to put it back together the more photos the better for awkward jobs like this... unfortunately it's a sod to do as you will find out .....

You could try these people for advice as they will no doubt come across what you want to do before.