Roof Tents should NOT be fitted to vehicles with clamp-mount roof bars
Roof top tents are becoming increasingly popular, but we advise they should not be carried on vehicles that use clamp-mount roof bars. There is too much risk of damage to the roof, which would also be a massive safety issue because the roof bar clamps would not work correctly.
Clamp-mount roof bars
If you are reading these notes then your vehicle has a plain roof and uses clamp-mount roof bars.
Our advice is that plain roof vehicles are not suitable for carrying roof top tents; we only recommend fitting roof tents to vehicles with roof rails, fix points, T-tracks or gutters, because here the roof bars and the roof load sit on the roof welds, where the sides of the vehicle are welded to the roof part; these are strong points. Clamp-mount systems for modern cars often sit outside these roof welds, on the ordinary unreinforced roof steel towards the edges of the vehicle roof.
The danger is that a plain roof may well not be strong enough to cope with the static weight of a roof tent and the occupants. This weight can cause the roof bar feet to make dents in the roof, which not only damages the vehicle but means that the clamping plates can no longer work as designed, so the safety of the whole roof bar system is compromised.
The weight of a tent can easily be 65kg (hard top tents can be over 75kg) plus roof bars at 8kg and two adults at let’s say 90kg each, that’s a total 253kg, well over 3 times the typical 75kg dynamic loading limit. If there are three occupants at let’s say 80kg each then we get to 313kg.
We supply tents made by Thule and by Yakima, respectively the world’s biggest and second biggest car rack manufacturers. Their tent instructions state that clamp-mount roof bars are not suitable for plain roof bars - ‘DO NOT use’. These brands would not turn away business if this matter is not important.
Thule's guidelines or instructions should be available via the Fitting instructions and videos tab.
We realise that this advice is confusing because these specific instructions are part of Thule’s and Yakima’s roof tent instructions, but are not included in their roof bar fitting instructions. We also supply CRUZ and Atera roof bars; again, no mention is made of roof tents in their roof bar instructions.
It is the roof bar feet that can make dents in vehicle roofs, even though it is a roof tent plus human(s) that caused the overloading; where we have supplied the roof bars, customers may look to us for repairs to their vehicles. The safety implications are a much bigger worry for us than the vehicle damage implications, which is why the safe option is to advise that no roof tents should be fitted to clamp-mount roof bars – all roof tents are very heavy, and many or indeed most of them are heavier than Thule or Yakima tents.
We can only advise you; we can’t stop you from carrying inappropriate loads. But if you do purchase clamp-mount roof bars from us, and use them for carrying roof tents, even where you have informed us that you wish to carry a tent, it is reasonable that we will accept no liability for damage to the vehicle, to the roof tent, or to third parties. If in doubt, we suggest that you obtain a written statement from the roof tent supplier to the effect that their tent may be carried on clamp-mount roof bars; this should provide you with some ‘cover’ in the event of any need for a claim.
Roof top platforms
Full size platforms such as the Thule Caprock and the Yakima LockNLoad platform should also not be used on clamp-mount roof bars; they tend to be heavily loaded, and to be walked on.
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