It's Not a Roof Rack: Building a 3m x 2m Roof Platform on a Renault Master Van
Our customer has one rule: never call it a roof rack.
Fair enough. When you're bolting a 3m x 2m walkable aluminium deck to the roof of a Renault Master, "rack" doesn't do it justice. This is a platform you can stand on, work from and load up, and it was built almost entirely from standard ModBuild T-slot components.
Here's how it came together, and why T-slot aluminium was the right material for the job.
The Brief
A big, flat, walkable surface across the full roof of a Renault Master van. It had to be:
- Strong enough to take a person's weight (and then some)
- Low profile, with side rails to keep gear and people where they belong
- Weatherproof, with no leaks through the roof skin
- Serviceable and adjustable, because needs change
- Tidy, with a finished look rather than a bolted-together bodge
That list is what T-slot aluminium is for.
Step 1: The Foundation – 4040 "Powerhouse" Rails
The platform's backbone is two lengths of our Powerhouse 4040 T-slot profile, running the length of the roof. At 40mm x 40mm with a heavy-wall section, it's rigid enough to spread loads across the roof structure instead of concentrating them at single points.
Fixing to a van roof needs care. Our customer used Plus nut fixings to secure the rails, bedded in Sikaflex sealant so every penetration is sealed against water. The result is a solid mechanical connection that stays watertight.
The T-slot channel also makes alignment easy. Fixings can slide to exactly where they need to be, rather than being dictated by where a hole happens to be drilled.
Step 2: The Deck – Personnel-Rated Aluminium Grating
With the rails down, the walking surface went on: personnel-rated aluminium walkway grating, secured to the 4040 rails with ModBuild T-nuts and fasteners.
This is where T-slot really shows its versatility. There's no welding, no custom brackets and no drilling into the rails. The T-nuts drop into the slot and slide to position, so the grating can be fixed wherever the mesh layout needs it. It's also fully reversible. If the customer ever wants to re-lay, extend or modify the deck, it's a spanner job, not a fabrication job.
Aluminium grating is also a smart choice for a vehicle. It's lightweight, drains water and debris, grips underfoot in wet weather and won't rust.
Step 3: The Finish – Die-Cast Aluminium Endcaps
A good build is finished properly. Our die-cast aluminium endcaps close off the open ends of the profile. They keep out water, dirt and debris, protect against sharp edges, and give the whole platform a clean, professional look.
It's a small detail, but it separates a project that looks engineered from one that looks improvised.
Step 4: Side Rails – 4080 Profile
For the low side rails, our customer used 4080 profile. The deeper 40 x 80 section is stiff for its weight and gives a solid edge to the platform, and it uses the same fixings and accessories as the 4040. Because the whole system shares one slot standard, everything works together without special parts.
The Deflection Test
Every engineer has their preferred method of load testing. Ours is a very happy customer jumping up and down on the finished platform.
It's not a certified test, but the grin says plenty. The platform held firm, with no wobble or complaint, just a van roof carrying a person comfortably at full bounce.
Why T-Slot Works for Projects Like This
This build shows why T-slot aluminium is so popular for custom projects:
- Strong and light: high rigidity without the weight penalty of steel, which matters on a vehicle.
- Corrosion resistant: aluminium handles Australian weather, sun and salt air.
- No welding required: everything bolts together, so you can build in the driveway with basic hand tools.
- Infinitely adjustable: slide, reposition and refit without drilling new holes.
- Modular and expandable: want to add tie-down points, a ladder mount, lighting, a solar panel bracket or an awning? Just add more profile and T-nuts.
- Cleaner finish: consistent profiles, matching endcaps and accessories give a professional look.
The same system that built this platform builds machine frames, workbenches, enclosures, camper fit-outs, trailer racks and workshop shelving. The ideas scale from a small bracket up to a full 3m x 2m deck.
Build Your Own
Whether you're planning a van platform, a ute rack, a trailer deck or something we haven't seen yet, we can help you spec the profile, fasteners and accessories to suit.
Browse our T-slot range at www.tslotmodbuild.com.au or get in touch with your project details and we'll help you work out what you need.
