Transporting plywood on the roof of your car can be an intimidating task. Plywood is very heavy and generates massive amounts of wind resistance. As a rule, it is best to transport large cargo like plywood in a truck or trailer. However, you can safely transport a few sheets of plywood on your roof rack as long as the travel distance is short and the load is properly secured.
Examine your roof rack and the size of your vehicle. Plywood sheets are large and heavy, meaning they can cause damage to your roof if the car cannot support the weight. If the roof rack is made of plastic or does not seem to be firmly attached to the car, it may be best to find a friend with a truck.
Consider the amount of plywood you need to move. While you can get away with carrying two or three sheets of plywood on your roof rack, as the load gets larger the chances for rack failure or broken straps increase. Do not use a car for any load larger than two or three sheets.
Place the plywood sheets on your roof rack. Align the sheets so that the longest part of the wood matches the longest part of your car.
Wrap one of your ratchet straps around the width of the plywood sheets. Tighten the ratchet strap until the sheets are tightly bound together, making your cargo more stable.
Run the remaining three ratchet straps from one side of the roof rack to the other, over the plywood sheets.
Tighten each ratchet strap to secure the plywood. Be sure to use straps that are at least 10 cm (4 inches) wide to improve cargo stability and decrease the odds of breakage.
Drive to your destination slowly and carefully. If possible, avoid highways and stick to neighbourhood roads and city streets.