Planning and Installing a Roof-Top Setup

When setting up a roof-top system, it’s essential to do your research. Carefully plan and configure your setup before beginning the design, build, and installation—ideally through a reputable fitment centre.

Start by determining everything you’ll need in addition to your roof-rack, such as a roof-top tent, recovery tracks, solar panel, table, spade, jerry cans, gas bottle, awning, hi-lift jack, etc. Decide whether your load will be relatively light (which may allow for a light sport roof-rack) or fairly heavy (requiring a heavy-duty welded roof-rack).

Plan your layout to ensure balanced weight distribution. Place heavier items near the vehicle’s centre point, and always ensure you remain within the vehicle’s GVM (Gross Vehicle Mass).

Understanding Roof-Load Ratings

One of the challenges in sourcing and installing a roof-rack is the lack of clear information around vehicle roof-load ratings. Many manufacturers refer only to their roof-rail load ratings and not to aftermarket roof-rack loadings.

It’s important to understand that the manufacturer's stated roof-load rating has little to do with the structural roof-load capability (which is often more than twice the vehicle’s weight—designed to prevent collapse if the vehicle rolls). Instead, these ratings are primarily about dynamic forces and their impact on road holding.

There are two important dynamic ratings to consider: on-road and off-road. However, "off-road" is rarely clearly defined. Does it mean a dirt or gravel road, or technical 4x4 tracks? Some manufacturers use an unofficial off-road rating of 66% of the on-road load rating.

Common Issues and Legal Grey Areas

It’s clear that many, if not most, roof-top setups—especially those with roof-top tents—exceed the stated roof-load ratings of the vehicles they’re mounted to. This issue is compounded by the weight of the roof-rack itself.

That said, many vehicles with roof-top tents are equipped with aftermarket off-road suspension systems, which can improve dynamic stability both on and off-road.

Whether an item is mounted to the vehicle’s roof or canopy, if it sits above the roofline, it will affect the vehicle’s dynamic handling.

Some roof-top equipment manufacturers or suppliers do publish roof-load ratings, but these are often not backed by official vehicle manufacturer data. Ultimately, your safest route is to work with a reputable fitment centre—one that understands manufacturer specs and ensures your build stays within the vehicle’s GVM limits.

Questions That Remain Unanswered

The manufacturer’s specifications for roof-load ratings—especially for off-road use—are often difficult or impossible to obtain. While some will list roof-rail ratings, they typically don’t clarify whether this refers to static, on-road, or off-road conditions.

This raises several important questions:

• Why is it so difficult to get accurate roof-load ratings from manufacturers?

• What reference figures would an insurance company use if roof-load overloading is suspected during a claim?

• Why do so many vehicles on the road appear to have roof-top tents that exceed their load ratings?

Because of this lack of clarity, many people end up relying on the roof-rack’s own load rating. This makes it even more important to ensure the rack is fitted using the vehicle’s designated mounting points. Anything drilled or riveted into the roof—rather than properly mounted—is likely to fail under off-road conditions.

Regardless, liability still rests with the vehicle owner or driver. You are ultimately responsible for ensuring your setup is safe, legal, and roadworthy. Substantial roof loads can significantly affect handling, and you must adjust your driving style accordingly.

A Real-World Setup: My Experience

After extensive research, I began the process of designing, building, and installing my own roof-top setup through a 4x4 fitment centre.

The journey had a few hiccups—most notably, catastrophic failure (twice) of the first roof-rack brand I used (a full settlement was eventually reached via lawyers).

My current setup uses a custom-made welded K9 roof-rack. Mounted to it is a carbon fibre roof-top tent (to reduce weight), along with a solar panel, table, recovery tracks, awning, spade, gas bottles, lights, and more.

The layout was carefully designed for optimal weight distribution before fitment, resulting in a secure and evenly balanced load.

This configuration has now been rigorously tested over tens of thousands of kilometres—including corrugated dirt roads, numerous 4x4 trails, and extended tar road travel—over the course of nearly four years, without incident.

I always take the added roof-top load into account when driving with the tent fitted and avoid steep, off-camber obstacles. I adjust my driving accordingly.

When tackling serious 4x4 routes—especially those graded 4 or 5—I remove the roof-top tent entirely.

About the author

Danny Eldridge is a seasoned outdoor professional with a passion for responsible exploration and vehicle-based adventure. As a registered National Nature and Cultural Tourist Guide, Danny combines technical skill with a deep respect for the natural environment.