# Using roof rails to set up hammock

Has anyone experience with attaching a hammock to roof rails of a regular car?

I just bought a hammock for my next camping trip. I will be traveling mostly by car and sleep in a tent but wanted something to relax in outside of the tent or car and also might try sleeping in the hammock. My question is: Is it possible (i.e. safe for both, me and the car) to attach one side of the hammock to the roof rails of the car? This might make a lot of places hammock-feasible, as I‘d only need one additional tree.

I am pretty sure that I have already seen auch a set-up with a Jeep-like car somewhere. But the car in question is an Opel Astra with normal roof rails so I fear that the rails might not withstand the sideward pull a hammock would cause on them. Since it is a borrowed car from a family member, I really do not want to damage it.

• If you do it: ideally you want the hammock to be "behind" the car, parallel to the usual driving direction, and not - as would be intuitive - to the side of the car. This is because that's the load the roof rails are more designed to do Commented Jun 14, 2019 at 10:24
• Funny how no one mentions that the weight of the occupant might factor into the equation. Commented Jun 14, 2019 at 10:50
• @Hobbamok Thank you! That’s a good point. Commented Jun 14, 2019 at 11:56
• It might help if you could qualify this somehow. How much weight can the hammock take given the weight and design of the car? What other factors play a role? The type of ground the car is situated on? Assuming the hammock and other side are sufficiently strong, obviously.
– JJJ
Commented Jun 14, 2019 at 12:52
• @Hobbamok you could even tie off to both rails that way Commented Jun 14, 2019 at 14:29

The load limit for directly mounted roof bars is around 60kg - 70kg for ordinary (European) cars. Usually the load limit for rail mounted bars is lower, but that's for vertical and dynamic load. This is a static load so you're probably ok.

Basically if it was my own car and not in great condition I'd do it, attaching the hammock to the far rail and hanging over the near one. With a borrowed car I wouldn't.

On the other hand if you get a single support for your hammock such as crossed poles, and using a tree at the other end, you can certainly use the tow loop as an anchor as that's more than strong enough to take the load.

• Estate cars can have a higher limit - 100kg on my old Peugeot with permanent bars supported in 3 places. It's probably best to tie the hammock at the middle support for side loading. And they're quite overbuilt for supporting that sort of load statically. Commented Jun 13, 2019 at 11:48
• @ChrisH, as you say, dynamic and static loading matters. Commented Jun 13, 2019 at 12:58
• Orientation matters - if you can arrange the direction of pull to be more in line with the car's axis, you're at much less risk than when loading at 90° (full abeam) to the vehicle. Check that you're not fouling the boot opening, though, or you'll curse yourself every time you need to get something out! Commented Jun 13, 2019 at 13:25
• Also, check that you take the hammock down before trying to dive to the grocery store the next day, or else you'll hear a distinct eee...eeeeeee.... BOOOOM! as the line snaps. Ask me how I know. Commented Jun 13, 2019 at 20:14
• @dwizum Obligatory question: Was the hammock occupied? Commented Jun 14, 2019 at 13:23

I would attach rope to both rails and perhaps even the door pillar on the opposite side. This would help spread the load if you’re worried about weakening the rail.

Update: In fact why not just tie across the roof to the opposite door pillar and simplify the task. One knot.

• Automotive body tin is fairly thin. Excessive pressure at some points can cause dents. Ok if you own the car maybe, NOT ok if it is a borrowed car. As mentioned in the answer by @mikeB it can also rub of paint. Commented Jun 14, 2019 at 13:52
• +1 and use flat webbing instead of rope to reduce the point pressure. Commented Jun 14, 2019 at 18:06
• +1 Or put a towel between the rope and the car body on the points of highest pressure. Commented Jun 14, 2019 at 20:50
• Also a small piece of wood board (or even cartonage) can help distribute the load. Commented Jun 15, 2019 at 20:19

I have done this on my 3 series wagon. I had the strap tied around the middle vertical support of one of the side rails. I also have cross bars installed, so I don't know if that helps in anyway to reenforce or distribute some of the load to the other rail, but I didn't have any issues. I just made sure that the strap was situated in a way where it came over the top of the bar so that it wouldn't rub on the paint of the roof.