Assess your rack situation.
How to tie lumber to roof rack.
Load your sheet of plywood on the roof rack.
Use a tie down that wraps around the item and the rails.
That prevents the bundle from sliding forward backward or side to side.
Then i use the nylon web tie downs i ve got in the photos of below.
Place 2 pieces of wood about 8 foot long on the roof rack on the lengthwise.
Ideally you ll have some kind of roof racks to tie things onto.
My car with roof rack with cross bars installed.
I use 4 hand clamps at the corners to hold the plywood to the 2 x 4 s.
On each side of the roof you ll see a rack that runs the length of the roof of the vehicle.
The second option is the side racks.
Nylon rope also works but be prepared to tie some trucker s knots.
Oh and remember to prepare two other pieces of wood for later use.
A pair of 20 web ratchets used as a fail safe in case the board slides to the rear of the vehicle.
Wood also advises against bungie cords as they re too prone to flex when driving at speed and causing loads to shift and possibly escape.
Then secure the front and back ends of each lumber bundle with ratchet straps to prevent movement photo 1.
Next secure the load to the rack using ratchet straps photo 2.
There are really three kinds of scenarios for your roof wood said.
Start by loading dimensional lumber onto the rack with the narrow edges resting on the crossbars.
Don t know if i d carry much lumber on that short front to back rack but i would definitely use at least two good ratchet straps ratcheted very tight around the lumber bundle so nothing could slip out.
Second trip 16 2 x4 x6 boards on my roof rack.
Secure it to the roof rack.
That s in addition to then attaching the bundle securely to the rack.
These are great for a lot of reasons but mostly because they give you something solid to anchor to so that your roof mounted load.
Remember to place a distance of about 3 to 3 foot in between.
4 web ratchet straps in a pair of x formations to hold down the board to the cross bars.
Plus the tiedown to the trailer hitch.
My car with 4 x8 mdf board on the roof rack.