I transport 4x8 plywood on my roof racks i usually run a couple of 2x4s under the roof racks the full length of the ply and strap to those at the front and back as well as strapping to the actual roof racks.
Transporting plywood on roof rack.
Tighten each ratchet strap to secure the plywood.
In case you have no idea how much weight your plywood sheet is a sheet of inch plywood is approximately 100.
Remember to place a distance of about 3 to 3 foot in between.
On a roof rack step 1.
A pair of 20 web ratchets used as a fail safe in case the board slides to the rear of the vehicle.
Drive to your destination slowly and carefully.
4 web ratchet straps in a pair of x formations to hold down the board to the cross bars.
Ask for help from friends if.
This project satisfies all three goals of most of my projects.
Hauled a lot of plywood that way even put longer 2x4 s on once and carried a 10 foot wide garage door.
As an alternative to tying you could attach these with duct tape.
Be sure to use straps that are at least 10 cm 4 inches wide to improve cargo stability and decrease the odds of breakage.
I needed to lug home some 1 2 sheets of fragile yet flexible 4 by 8 drywall with only my honda civic.
Secure it to the roof rack.
Second trip 16 2 x4 x6 boards on my roof rack.
Place two 8 foot long 2 4 pieces of dimensional lumber on the roof rack lengthwise.
My car with roof rack with cross bars installed.
The method you use to secure the lumber will depend on what kind of roof rack you have.
Rusticdavid woodworklessons woodworkingforbeginners david shows how to tie wood boards and sheets of plywood safely and securely to your cars roof rack dav.
Out of the choices of cheep quick and good you usually only get to pick two.
Run the remaining three ratchet straps from one side of the roof rack to the other over the plywood sheets.
There should be a 3 to 3 foot span between the 2 x 4 s.
When i had a car with thule racks i set up 2 4 foot 2x4 s that bolted flat on top of the cross bars.
Use ratchet straps that can handle the weight of your load and check that the roof rack is secure enough to provide a proper anchor.
I would lay sheets of plywood on these bars and then use a c clamp at the end of each 2x4 to clamp the plywood to the 2x4 s.
Makes it a lot harder for the winds to lift it up.
Just make sure to follow the same basic principles outlined above.
My car with 4 x8 mdf board on the roof rack.