What Is Covert Vehicular Storage Architecture? (Truck Voids)
Covert vehicular storage architecture, sometimes called “truck voids,” refers to unused or altered spaces within a truck body. The term is informal, not a standard engineering category. Building hidden compartments can compromise crash protection or obstruct vehicle systems, so I can’t provide concealment plans. For lawful cargo, choose visible, manufacturer-approved storage installed and checked by a qualified upfitter.
Adding storage can be a worthwhile investment when it protects tools, keeps cargo from shifting, and makes daily work easier. But a space that looks empty behind a trim panel or beneath a floor may contain wiring, airbag parts, fuel-system components, cooling paths, or structural members. Altering it without approval can create risks that are hard to see during a casual inspection.
The safest way to approach “truck voids” is to separate the term from a build plan. It may describe a gap inside a vehicle body, but it does not mean the space is safe, legal, or available for storage. Below, I explain how to assess a truck for an overt, secure upfit instead.
What “Truck Voids” Means
“Truck void” is a casual term for an apparent unused space within or around a truck body. It is not a universal vehicle-design term, nor does it establish that a space is suitable for cargo. Vehicle layout, body style, and equipment differ, so the meaning must be checked against manufacturer information.
People may use the phrase for gaps behind interior panels, beneath a cargo deck, or within a commercial body. Those areas can hold parts or provide clearance for systems that need to move, cool, or remain accessible. A cavity’s size alone does not show whether it can safely carry an object.
This also differs from an approved storage compartment. An approved compartment is designed for a stated purpose, has an intended access method, and can be secured in a way that suits the vehicle and load. A space found during a teardown does not gain those features just because it seems convenient.
There are no universal IRC, IBC, or NEC dimensions for truck-body voids. Those codes address buildings or electrical work in particular settings; vehicle rules depend on the vehicle class, jurisdiction, and type of change. Check the maker’s body-builder guidance and ask a qualified upfitter which requirements apply.
Planning a Compliant Truck Storage Upfit
Planning means defining the cargo and checking the vehicle before choosing a storage product. Start with the vehicle identification, intended load, payload limits, and manufacturer upfit guidance. The goal is storage that stays secure, preserves vehicle systems, and remains accessible for use and service.
First, list what the truck will carry, including the weight and size of each item. Do not estimate by appearance when a scale or product specification is available. Include the weight of racks, drawers, toolboxes, liners, and other installed equipment in the vehicle’s loaded weight.
A basic payload check is:
Available payload = gross vehicle weight rating (GVWR) minus the truck’s current operating weight.
Use the vehicle maker’s definitions and labels when doing this calculation. The result is not the only limit. Front and rear gross axle weight ratings (GAWR) also matter, as does how the load is distributed. A truck can be below its GVWR yet exceed an axle rating.
| Planning item | What to verify | Why it matters |
|---|---|---|
| Vehicle identity | Make, model, year, body style, and configuration | Upfit guidance can vary by vehicle |
| Cargo | Item weight, size, and intended use | Helps select suitable storage and restraints |
| Capacity | GVWR, axle ratings, and current loaded weight | Limits the total load and its placement |
| Mounting | Approved points and hardware requirements | Reduces risk of damage or loose cargo |
| Service access | Required access to panels and components | Avoids blocking maintenance or inspection |
A storage maker’s advertised capacity does not override the truck’s limits. Nor does a sturdy-looking mount prove that the underlying body structure can take the load. Ask the upfitter to confirm both product ratings and vehicle-specific mounting requirements before purchase.
Access, Service Zones, and Occupant-Safety Clearances
A service zone is an area that must stay open or reachable for vehicle operation, repair, or inspection. Occupant-safety clearance means preserving the space and function needed by belts, airbags, seats, and other safety systems. A proposed storage location must respect both, even when it appears unused.
Have a qualified technician survey the planned area before any panel, floor, or trim is altered. The survey should check structure, wiring, fuel-system parts, airbags, cooling paths, and service-access zones. An airbag sensor or wire may not be visible from the cargo side, and a structural member may be hidden behind trim.
Do not cut, drill, cover, or load a suspected structural member or vehicle system based on appearance. Enclosing a component can also block inspection or service. If the manufacturer’s guidance does not clearly approve the proposed change, pause and seek a qualified engineering review or a different storage location.
| Area or system | Safe planning question | If the answer is unclear |
|---|---|---|
| Airbags and restraints | Could storage alter deployment space or wiring? | Do not modify; ask the vehicle maker or qualified technician |
| Fuel system | Could the work contact or enclose fuel parts or lines? | Stop and arrange a professional survey |
| Electrical wiring | Could drilling, pressure, or heat damage a harness? | Use approved routes and installer guidance |
| Structure | Is the proposed mount approved for this body area? | Do not cut or attach until verified |
| Service access | Can technicians reach required parts as intended? | Choose a different storage product or location |
There is no single clearance measurement that applies to every truck void. Space needs depend on the vehicle and system. The practical next step is to identify the exact vehicle and have its maker’s guidance reviewed before selecting a location or mounting method.
Installation by a Qualified Vehicle Upfitter
A qualified upfitter adapts commercial vehicle bodies and equipment to a specific vehicle. For storage work, that person should understand the vehicle’s body-builder information, mounting limits, electrical routing, and cargo needs. The right installer can also identify when a requested change needs engineering review or should not proceed.
A safe sequence is straightforward:
- Identify the vehicle, intended lawful cargo, payload limits, and applicable manufacturer or upfit requirements.
- Have a qualified technician survey the structure, wiring, fuel system, airbags, cooling, and service-access zones.
- Install clearly accessible storage using approved mounting points and hardware rated for the vehicle and load.
- Inspect for interference, securement, serviceability, and compliance, then document the modification.
Use storage made for the intended vehicle or a clearly documented upfit. Follow the product maker’s instructions, including limits on load and mounting. Avoid improvising fasteners or relying on interior trim as a load-bearing mount unless the vehicle and product guidance specifically allows it.
A useful installer conversation includes these questions:
- Which vehicle-specific guide supports this location and mounting method?
- What is the storage unit’s rated capacity, and how is it attached?
- Will the installation affect airbags, wiring, fuel parts, cooling, or service access?
- How will the cargo be restrained during normal driving and sudden stops?
- What inspection or records should I keep?
If the installer cannot answer these questions, seek another qualified professional. A neat appearance is not proof of structural safety.
Inspection, Securement, and Documentation
Securement means holding cargo and storage in place with a method suited to the vehicle and load. Inspection checks that the installation does not interfere with vehicle systems and remains serviceable. Documentation records what was installed, how it was mounted, and which guidance or product instructions were used.
After installation, confirm that doors, seats, belts, and other controls work as intended. Check that storage does not block service panels or create contact with wiring and nearby parts. Have the upfitter verify the attachment and cargo restraint rather than relying on a visual check alone.
Keep a record of the storage product, its rating, installer details, mounting approach, and any review or approval documents. This can help a future technician understand the change. It can also make repairs and later inspections more efficient.
Recheck the installation as the product maker or upfitter advises, and after any event that may have shifted or damaged it. If a mount loosens, a panel changes shape, or a new noise appears, stop using the storage until it has been inspected. Do not treat a one-time check as a guarantee for the life of the vehicle.
Illustrative Upfit Scenarios
These examples are planning scenarios, not reports of specific client installations. They show how to apply the same safety checks to different truck uses.
Pickup used by a tradesperson: The owner needs room for hand tools and wants quick access during the workday. A visible, vehicle-compatible toolbox or drawer system can be compared by capacity, mounting method, and effect on payload. The installer checks mounting points and confirms the system does not interfere with cab or bed functions.
Commercial box truck: A crew needs organized space for equipment used on repeat service calls. The upfitter reviews the body maker’s guidance, cargo weight, attachment method, and access to service areas. Fixed storage is selected only after the vehicle and body requirements are checked.
In both cases, the right answer depends on the specific truck, load, and manufacturer guidance. A product that suits one body style may not suit another.
Common Questions About Truck Voids
Are truck voids a standard engineering term?
No. “Truck void” is informal language for an apparent gap or unused area. It does not identify a rated storage space or confirm that the area is safe to alter.
Is every empty cavity safe for storage?
No. It may contain wiring, safety equipment, fuel-system parts, cooling paths, or structural members. A qualified technician should survey it before any modification.
Are there universal dimensions for truck-body voids?
No. There are no universal IRC, IBC, or NEC dimensions that make a truck-body cavity suitable for storage. Vehicle-specific guidance and local requirements may apply.
Can I use GVWR alone to decide how much cargo to add?
No. Check the truck’s GVWR, axle ratings, current loaded weight, and maker guidance. Load placement can affect axle limits even when total weight is within GVWR.
What should I ask an upfitter before installation?
Ask how the location and mounting method match the vehicle maker’s guidance, what the storage unit is rated to carry, and whether the work affects safety systems or service access.
Can a storage unit be mounted to any flat surface?
No. A flat surface may be trim or a panel that cannot support the load. Use approved mounting points and hardware selected for the vehicle and intended cargo.
What if the manufacturer’s guidance does not cover my proposed change?
Do not assume the change is acceptable. Ask a qualified upfitter whether an engineering review is needed, or choose a storage option already approved for that vehicle.
What records should I keep?
Keep the product information, capacity rating, installer details, mounting documentation, and any applicable review or approval records. These can help with later service and inspection.
Does an upfit automatically comply with every rule?
No. Applicable requirements depend on the vehicle, modification, and jurisdiction. Have the upfitter identify what applies and document the work.
Conclusion
A truck’s apparent void is not automatically storage space. Treat the term as a prompt to check, not a plan to modify. Identify the vehicle and cargo, verify capacity and manufacturer guidance, and use an overt, securely mounted storage system installed by a qualified upfitter. When a cavity’s purpose is unclear, leave it unaltered until it has been assessed.
(This article was written by one of our staff writers, Garrett Vance. Visit our Meet the Team page.)
