Your floor is the foundation of your build - literally. It goes in first and everything else sits on top of it. Choose something durable, water-resistant, and that you won't mind looking at every day.
Your van floor needs to handle everything from muddy boots and spilled coffee to being walked on constantly. It needs to be waterproof (or at least water-resistant), durable, easy to clean, and not too heavy. It also needs to look decent since you'll be staring at it every day.
Luxury vinyl plank (LVP) is the best choice for most van builds. It's waterproof, durable, easy to install, looks great, and costs $1-3 per square foot. Unless you have a specific reason to choose something else, go with LVP and spend your energy on other decisions.
LVP has become the dominant flooring choice in van builds, and it's easy to see why. It's engineered specifically to handle moisture, heavy traffic, and temperature swings - exactly what a van floor deals with.
My take on laminate: The $0.50-1 per square foot savings over LVP isn't worth the water damage risk for most van builds. In a van, water will get on your floor - wet boots, rain, spills, condensation. Laminate can handle occasional light moisture, but it's not built for the kind of exposure a van floor sees. Save the $20-40 extra for the peace of mind of LVP.
Rubber flooring (coin-top, diamond plate, or flat rubber rolls) is popular in adventure-focused builds. It's the most utilitarian option and handles abuse better than anything else.
Rubber is great for the "garage" section of your van if you have a separate living area up front. Many people do a split floor: rubber in the back where bikes, gear, and muddy boots go, and LVP up front in the living area.
Some builders choose real hardwood flooring for aesthetics. It can look absolutely stunning, but it comes with significant drawbacks in a van environment.
I generally don't recommend real hardwood in a van. It's expensive, heavy, can warp and cup with humidity changes, needs to be sealed carefully, and doesn't handle water well. Modern LVP looks almost identical to real wood and handles the van environment much better.
If you absolutely want real wood, use an engineered hardwood (thin hardwood veneer on plywood core) rather than solid hardwood. It's more dimensionally stable and less prone to warping with humidity changes.
Your finish flooring sits on a subfloor, which sits on top of insulation, which sits on the van's metal floor. A few things to keep in mind:
Go with luxury vinyl plank. It checks every box: waterproof, durable, attractive, affordable, easy to install, and easy to replace. Get a quality brand with 4mm+ thickness and attached underlayment.
For adventure builds: Consider rubber flooring in the "garage" area and LVP in the living space. Best of both worlds.
Skip laminate unless budget is extremely tight. The water damage risk in a van just isn't worth the small savings.
Your floor is one of the first things to go in and one of the hardest to change later. Spend the extra $20-40 to do it right.