Yes, you do need the right roof bars for a roof tent, but not necessarily "special" ones. The important things are:

1. The dynamic load rating: your bars must be rated to carry at least the weight of the tent while driving, and for most roof tents that means bars rated 75kg or more. Some bars are rated at only 50–75kg, so check your rating before you buy a tent, not after.
2. Aluminium Aero roof bars with an oval shape are the best option for roof tents. Steel 'square bars' can bow under sustained weight over time, which will affect fit and performance.
3. Through bar design - the bars should extend over the roof bar roof, rather than stopping at the foot, so the weight is supported on top of the foot.
4. Good quality bars by a reputable manufacturer. We almost exclusively recommend Thule WingBar Evos.

We fit roof tents for customers almost every week at our Cornwall showroom, and roof bars are the number one thing people get caught out by. Here's the full picture, in plain English.

Dynamic vs static load: the only two numbers that matter

Every set of roof bars (and every car roof) has two different weight limits, and confusing them is where most of the myths about roof tents come from.

The dynamic rating is the one that decides whether your car can carry a roof tent, because that's the limit that applies on the road. The static rating is what applies when you're actually sleeping in the tent , and because a parked car isn't absorbing potholes at 60mph, roofs can support far more weight when stationary. That's why two adults can happily sleep in a roof tent on bars rated at 75kg: overnight, the load is static, spread across the bars and into the strongest parts of the roof structure.

How much do roof tents actually weigh?

Here are the approximate weights of the TentBox range we stock and fit in Cornwall (always check the current spec on the product page, as weights change slightly between model years):

The rule is simple: your bars' dynamic rating must be equal to or higher than the weight of the tent. Nothing else goes on the roof while a tent is fitted, so the tent's weight is the whole calculation.

What to look for in a set of roof bars

1. Dynamic load rating

Printed in the bars' manual or on the manufacturer's website. Remember you're checking three ratings, and the lowest one wins: the bars themselves, the foot/fitting kit, and your car's roof (in the vehicle handbook).

2. The right fit type for your car

Roof bars attach in one of four ways: raised rails, flush rails, fixed points, or bare-roof (door-frame) clamps. The bars must match your car's fit type. This is about attachment, not strength, but the wrong kit simply won't mount securely. If you're not sure which your car has, our guide to which cars fit a roof tent covers it, or send us your registration and we'll check for you.

3. Bar spacing

Most roof tent manufacturers recommend the two bars sit at least 70cm apart where the vehicle allows it. Wider spacing spreads the load better and reduces flex. On shorter cars this isn't always achievable, it's one of the things we check during a fitting.

4. Bar profile

Aero and wing-profile bars work with roof tents as long as the rating is there. Square Bars are not recommended. Roof tent mounting plates clamp around most common profiles.

Do factory-fitted bars work?

Sometimes. Factory crossbars on SUVs and estates are often rated at 75–100kg dynamic and are absolutely fine for lighter tents. But plenty of factory bars, especially on smaller cars, are rated at 50kg or lower, and some are designed more for roof boxes and bikes than a permanent tent. Check the handbook figure rather than assuming. One extra caveat: cars with panoramic glass roofs sometimes have reduced roof load limits, so the handbook check matters even more there.

A quick word of caution: roof load limits are a safety matter. The figures above are general guidance, not advice for your specific vehicle. Always confirm the ratings in your car's handbook and the bar manufacturer's documentation, and if in doubt, ask a professional fitter.

Not sure? That's literally what our showroom is for

This is the part of roof tent buying that's hardest to get right from a website spec sheet, and it's why Robin & Mel run a physical showroom in Cornwall rather than an online-only shop. Tell us your car and the tent you're considering, and we'll confirm the correct bars and fit kit before you spend a penny. We also offer a professional installation service, so bars and tent go on properly, torqued and checked. And if you'd rather try roof tent life before committing, Bruce our roof-tent-equipped hire car, comes with all of this already sorted.

Frequently asked questions

Do I need special roof racks for a rooftop tent?

Not special ones, but suitable ones: crossbars with a dynamic load rating at least equal to your tent's weight (75kg+ covers most models), matched to your car's fit type. Standard quality bars from brands like Thule work well if the rating is sufficient.

What roof bars do I need for a roof tent?

Two crossbars matched to your vehicle's fit type (raised rails, flush rails, fixed points or bare roof) with a dynamic rating above your tent's weight, ideally spaced 70cm or more apart. The lowest rating among bars, feet and your car's roof is your real limit.

Can you put a rooftop tent on any roof bars?

No. Bars rated below the tent's weight aren't safe for driving, even if the tent physically clamps on. Always check the dynamic rating of the bars, the fitting kit and the vehicle roof before fitting a tent.

How much weight can roof bars hold?

Typically 50–100kg while driving (dynamic load), depending on the bars and the vehicle. When parked, the static capacity is several times higher, which is why sleeping in a roof tent is fine on properly rated bars.

Can you fit a roof tent on a car with a panoramic roof?

Often yes, but panoramic roofs can come with reduced roof load limits, and some cars with full-glass roofs have no mounting points at all. Check your handbook, or ask us to look up your specific model.