Hi, I was thinking about this recently, is there a recommended technique for securing stuff on your car`s roof racks? Like when transporting flat shelf or pieces of wood, or a small boat. It would be great not to know the best knot, but also the way around cargo the rope should follow to firmly secure it in place.
My first option would be to use ratchet straps:
I'm not sure what they're called in Croatia but they generally look like that. That's a lightweight one, suitable for car roof racks. They come in all sorts of variations: different hooks, different load restraint capabilities, different sizes.
I would have one at the front and one at the rear, going across the load from side to side, as a minimum. Depending on the load (e.g. sheets of wood) I may also have one going around the load front to back in the middle, so from above it looks like ‡ .
If you're carrying a long boat, like a
canoe, I would tie each end of it to the car as well; either run a rope or the tail of the ratchet strap to the front and rear and tie to the roof rack, or use the front towing eye of your car and whatever you've got on the rear (mine has a towbar so I'd use that).
Find out how much your car can carry on its roof; most have a limit of around 50kg. Obviously the more weight you put up top the more the handling is affected, and think about the airflow around the load - a sheet of wood not strapped down correctly could flip off the top of the car when the air gets underneath it, like a Mercedes at Le Mans in 1999.
---------
If you want to use rope, I would use a
dolly knot (also called a trucker's hitch). Finish it off with a couple of
half hitches. You can do that around the end of the roof bar.
