“What makes your trucks so special? They look like a lot of others. Why do they sometimes cost more?”
That is the question we get asked more than any other. It is a fair one. Two finished food trucks can look almost identical in a listing photo and be thousands of dollars apart, and from the outside there is no way to tell why.
The honest answer is that most of what you pay for in a food truck disappears behind the walls before the truck is finished. So we filmed it before it disappeared. This is the first episode of What You’re Paying For, a short series from inside our shop, and it covers the three things that go in first: the steel frame, the subfloor and the trim.
Watch the episode
Van walls were never meant to carry a kitchen
The truck in this episode is a Ram ProMaster cargo van that is on its way to becoming an acai bowl truck. Next to it in the shop is a second build a few weeks further along, so you can see the same parts once they are covered up.
The walls of a cargo van are thin sheet metal. They are there to keep the weather out of a box that carries parcels, and that is all they were designed to do. A food truck asks a lot more of them. The service window, the counters, the hood, the shelves, the refrigeration and the water tanks all have to hang off something, and on the road every one of those things is being shaken, braked and cornered with all day long.
So before anything goes in, we build a steel skeleton inside the van. It is 1 inch by 1 inch steel, tied into the chassis, running up the walls and across the roof. The frame carries the load. The van walls just stay walls.
Heavier steel where the load is heavier
Not every part of the truck works equally hard, so the steel is not the same everywhere. The generator box and the service window are the two places that take the most abuse, and both sit in frames of heavier 2 inch by 1 inch steel.
The service window is the clearest example of why. The simplest way to fit a window to a van is to cut a hole in the side and screw the window into the sheet metal. It looks fine on delivery day. But that thin panel is now holding a heavy glass window that gets opened and slammed shut every service, on a vehicle that hits potholes for a living. A few years later the opening starts to sag, then the window rattles, then it leaks. Framing the opening in steel first means the window is held by the frame, not by the skin of the van.
A subfloor, because van floors are corrugated
The floor of a cargo van is corrugated steel, ridges and channels designed to stiffen a thin sheet. You cannot bolt a three compartment sink or a refrigerator flat to ridges, and you cannot lay a food grade floor over them and expect it to stay flat.
So the first thing that goes down is a three quarter inch subfloor across the full length of the truck. On top of that goes aluminum diamond plate, and the equipment is mounted down through it with washers. A sink or a fridge that is fixed to the floor stays where it was put. One that is just set in place walks across the truck a little more on every drive.
Trim on every seam
The last part of this episode is the finish work, which is the part buyers are most likely to see and least likely to notice. A food truck is lined with panels, and wherever two panels meet there is a seam. Every one of those seams, on the walls and across the roof, gets a trim piece.
The reason is cleaning. Leave a seam open and grease, flour and grime work their way in behind the panels, and you cannot clean what you cannot reach. That is a hygiene problem long before it is a looks problem, and it is the kind of thing a health inspector notices. Every one of those trim pieces is made in our shop, cut to fit that truck.
Why none of this shows up in a listing photo
Once the walls, the floor and the equipment are in, every part of this work is covered up. A photo of a finished truck shows the wrap, the window and the stainless, and those look much the same whether the window is held by a steel frame or by the van’s sheet metal, and whether the floor is sitting on a subfloor or straight on corrugated steel.
That is why two trucks that look the same can be priced differently, and why a cheaper build is usually cheaper somewhere you cannot see. None of it shows up in a listing photo, but you feel all of it a few years in, every time a window sticks or a panel lifts or a piece of equipment works loose.
Questions to ask any builder
If you are comparing quotes, these are worth asking whoever you talk to, including us:
- Is there a steel frame inside the walls, and is it tied into the chassis?
- How is the service window opening framed?
- What goes down between the vehicle floor and the finished floor?
- Is the equipment mounted to the floor, or set in place?
- Are the seams between panels trimmed, and who makes the trim?
- Can I see a truck partway through the build, before the walls go on?
The last question is the most useful one. Any builder can show you a finished truck. Ask to see one in the middle.
What a build like this costs
Custom food trucks start at $55,000 and custom food trailers start at $40,000. A typical 16ft truck comes in around $72,000, and a large 22ft build with a full equipment package runs closer to $110,000. The framing, subfloor and trim in this episode are part of every one of those numbers, not an upgrade. If you want to see how the rest of a price comes together, the cost calculator below breaks it down by size and equipment.
Coming up in the series
Each episode takes one thing that goes into our builds and does not show up in the photos, and shows why it is there. Topics we want to get to include why every wire runs in conduit, what goes inside the walls, why every piece of equipment gets its own breaker, and where the propane goes and why. If there is something you have always wondered about on a food truck, ask in the comments on the video and it may be the next episode.
Frequently asked questions
Why do some food trucks cost more than others that look the same?
Because most of the difference is behind the walls. A steel frame inside the vehicle, framed openings for the window and generator box, a subfloor under the finished floor and trim on every panel seam all add cost, and none of them show in a photo of a finished truck.
Why does a van food truck need a steel frame inside?
Cargo van walls are thin sheet metal designed to keep weather out, not to carry a service window, counters, a hood and equipment. A steel frame tied into the chassis carries that load so the van walls do not have to.
What happens if a service window is mounted straight to the van sheet metal?
It usually looks fine at delivery. Over time, with the window being opened and closed every service and the truck on rough roads, the thin metal around the opening can sag, then the window rattles and eventually leaks. Framing the opening in steel first avoids that.
Why does a food truck need a subfloor?
Van and truck floors are often corrugated steel, which is not flat. A three quarter inch subfloor gives a flat, solid base for the aluminum diamond plate floor and something to mount the equipment to.
Why are the seams between food truck wall panels trimmed?
An open seam lets grease, flour and grime get behind the panels where they cannot be cleaned. Trimming every seam keeps the inside of the truck cleanable, which matters to the health department as well as to the owner.
What should I ask a food truck builder before buying?
Ask whether there is a steel frame tied into the chassis, how the service window is framed, what is under the finished floor, whether the equipment is mounted down, whether the seams are trimmed, and whether you can see a truck partway through the build.
More reading
- Food truck cost calculator: build price by size and equipment
- Food truck monthly operating costs in 2026
- Build videos: walkthroughs of recent trucks
- A Ford Transit van build, framed the same way
- A 10ft Sprinter coffee van conversion
If you are comparing quotes and want to see what is behind the walls of one of ours, call or text and come and see a truck in the middle of a build. We have built around 500 food trucks, trailers, bus conversions and van conversions.
Jacob Varghese
Zion Foodtrucks
719-722-2537