Van Conversion Guide

Base Build

Why Install a Subfloor?

A subfloor creates a solid, level base for your van’s flooring and cabinetry. It protects any insulation underneath, gives you a smooth surface to build on (instead of dealing with the van’s ribbed metal floor), and generally makes the rest of your build much easier and cleaner.

Different Materials

1. Tongue & Groove Particle Board

  • 25mm thick with interlocking edges for a flat, even finish

  • More affordable than marine ply

  • Downsides: absorbs moisture easily and takes up more headroom

2. Marine or Structural Plywood

  • Straight, strong, and highly moisture-resistant

  • Can be used in thinner sheets (e.g. 12mm), preserving valuable headroom

  • More expensive

Sub Floor

Priority Recommended Option
Maximising Headroom Marine/structural plywood (thinner, durable)
Budget-Friendly Standard plywood (as long as it’s flat and not warped)
Best Finish for Vinyl Tongue & groove boards (but must be primed for moisture protection)

🔧 Installation Tips

  • Framing/Packing If raising the subfloor to accomodate for insulation then it’s recommended to use plywood strips running East-West across the van’s ribbed bed pan. This reduces the contact between the timber with moisture as well as reducing thermal bridging. (Always join subfloor boards on a strip to avoid movement and squeeking)

  • Template first: Use the factory rubber floor as a template or make cardboard cutouts for tricky sections

  • No screws needed: Avoid screwing into the van’s floor pan—this can cause rust

  • Adhesive method: Use Sikaflex or similar polyurethane adhesive to secure panels

  • Seal it up: Apply silicone around edges to prevent moisture ingress

  • Optional insulation: You can insulate under the subfloor with thin foam (like XPS or closed-cell), but this will reduce headroom. Only strictly necessary if you’re concerned about cold floors.

A woman working inside an empty cargo van, using a tool with various tools scattered on the floor, plywood panels installed on the sides, duct tape, and a measuring tape in the background.

✅ Important: Prime both sides to prevent water damage if using Particle Board/Chip Board

Person working inside an empty van, leaning forward with hands on the van interior ceiling, surrounded by tools and materials for van renovation.

💡 Jake’s Tip: In smaller vans, saving headroom is everything. Go for thinner marine ply if you’re installing insulation under the floor—it gives you flexibility without the bulk.

A woman in sportswear working inside a partially gutted van, holding a wooden panel, with tools and a yellow measuring device on the floor.