The van already came with a floor in situ made of OSB board and we did think about replacing it with thicker wood but it does just fine, and especially since we've opted to floor with laminate which will give it extra rigidity. So we removed the original floor, filled in any random screw holes, and put down 4mm PET bubble insulation for additional coziness, fixed down with spray adhesive. We then used 18x34mm planed timber batons to support the floor, laid on top of the bubble insulation. The original floor was replaced and screwed down to the batons.
In terms of laminate, we've chosen Quick Step Aquanto laminate flooring in an oak colour. This laminate claims to be waterproof when installed using some super expensive Hydrokit silicone and has an abrasion rating of AC4 which means it's suitable for commercial/high traffic areas, so should be durable enough for the van even when in 'van mode' transporting tools and equipment.
We've used standard foam underlay, and have fixed this to the chassis of the van with foil tape to increase it's waterproof-ness should any water get under the laminate.
We also debated whether to lay the laminate lengthways or widthways. Lengthways would give a greater stability so we opted for this, with the joins in a random fashion pretty much just as you'd lay laminate in a house. The joins were sealed with this Hydrokit stuff, and it was also used around the periphery of the entire floor. So should be safe for mopping/wet feet/soggy doggies/spilling wine.
To give a professional sleek finish, the edges at the back and the side door of the van were finished with an aluminium trim which was screwed down.
