With the third option crossbars with side rails you can secure an item to the side rails and run tie downs from front to back securing them to the crossbars.
How to tie lumber on roof rack.
On each side of the roof you ll see a rack that runs the length of the roof of the vehicle.
If you have a small load of lumber then you won t have to do anything complicated.
Use a tie down that wraps around the item and the rails.
To avoid contact between the hook and the frame tie a figure 8 loop in the strap two feet from the hook run the hook end through the door frame and hook it onto the loop.
Oh and remember to prepare two other pieces of wood for later use.
That prevents the bundle from sliding forward backward or side to side.
Attach a ratchet strap to a rear anchor point on one side of the bed and lay it across the end of the bundle to the rear anchor on the other side.
Ask for help from friends if the sheet is too.
Secure it to the roof rack.
Next secure the load to the rack using ratchet straps photo 2.
Load your sheet of plywood on the roof rack.
Next pull the long end of the strap under the crossbar on the.
Wood says side rails and crossbars are ideal but you can move whatever you you need to without them.
In the case of a naked roof you should be looping the rope through the car through the doors not the windows and around the object on the roof and a towel or blanket should be used to protect the roof of your car from the object.
Place 2 pieces of wood about 8 foot long on the roof rack on the lengthwise.
Then secure the strap and tension it down to keep the load in place.
Start by loading dimensional lumber onto the rack with the narrow edges resting on the crossbars.
Remember to place a distance of about 3 to 3 foot in between.