Building a DIY Flat Roof Rack Using Unistrut

How I Built a DIY Flat Roof Rack for My Van Using Unistrut

A cost-effective and customizable alternative to retail roof racks


Why I Built My Own Roof Rack

After researching roof racks for my van, I found that many commercial options were either too expensive or didn’t fit my needs. I was looking for:

  • A flat platform (no raised side rails)

  • Longer-than-standard length

  • A durable, modular design

  • A lower overall cost

Initially, I considered using 4080 and 4040 aluminum profiles fixed together using a 4040 aluminum profile fixed base connection block, but the price added up quickly. That led me to discover Unistrut, a heavy-duty metal framing system often used in industrial applications. While heavier than aluminum, Unistrut is affordable, widely available, and highly adaptable — making it a strong choice for a DIY rack.


Materials Used

  • 5 x 3-meter Unistrut lengths (41mm x 41mm) - LINK

  • 2 x 4-meter Unistrut lengths (41mm x 41mm)

  • Black direct-to-metal paint - LINK 

  • M10 Metpro easyfit channel nuts (Unistrut-compatible) - LINK

  • 2 x Black 41mm x 41mm Stop Ends - LINK

  • 4 x 45° Obtuse Angle Brackets - LINK


Step-by-Step Build Guide

1. Cutting the Crossbars

I cut the five 3-meter Unistrut pieces in half, creating ten 1.5-meter crossbar sections — the perfect width for my van. I used an angle grinder and cutting blade

2. Painting

All metal pieces were coated with a black direct-to-metal paint to prevent rust and improve the visual finish. I used Hammerite Spray Paint Direct To Rust Aerosol

3. Mounting to the Van

I aligned four of the crossbars with the van’s existing roof rack mounting points. After drilling new holes as needed, I securely bolted the bars into place.

4. Attaching the Side Runners

The two 4-meter Unistrut pieces were used as side rails, running the full length of the van. I:

For the corners I used 90 Degree Flat Plate – Type (P1036) 
and I used the M10 METPRO EASYFIT CHANNEL NUTS and some M10 bolts, all with some Loctite

5. Adding Remaining Crossbars

I installed the remaining crossbars — one in the middle and one at the front — for added support and future mounting options.

6. Finishing Touches

To complete the build:

  • I installed 41mm x 41mm Black Stop Ends on the rear to seal off the channels

  • Mounted four 45° Obtuse Angle Brackets on the front crossbar so I could instal a metal wind deflector which I had cut to size by an online store.


Mounted direct to old roof brackets

The Flat Gusset/Delta Plate – Type (P1358)

90 Degree Flat Plate – Type (P1036)

The 4 45° Obtuse Angle Brackets holding on the wind deflector

The wind deflector with sticker for finishing touches.

Final Thoughts and Recommendations

This Unistrut roof rack turned out to be a strong, modular, and budget-friendly solution that fits the van perfectly.

✅ Benefits

  • Cost-effective compared to commercial racks

  • Flat, modular design allows for future add-ons

  • Solid and stable construction

  • Easy to adapt using standard Unistrut components

⚠️ Considerations

  • Heavier than aluminum options

  • Be mindful of total roof weight for safety and legal limits

  • Seal all exposed ends and paint to prevent rust or purchase the galvanised option.

🔧 Tips for Your Own Build

  • Plan your layout around existing roof mounts to reduce complexity

  • Use spring nuts and pre-threaded brackets to speed up assembly

  • Add a thread lock to each bolt to avoid any bolts self loosening 

  • Paint everything before assembly for better coverage and corrosion protection

Conclusion

If you're looking for a practical and customizable alternative to expensive pre-made roof racks, Unistrut is a strong option worth considering. With a bit of planning, basic tools, and patience, you can build a roof rack tailored exactly to your setup.

Comments

Post a Comment