Measure the length and width of the carport to determine the area of the roof in square feet. Multiply the length by the width to get the measurement for the area.
Determine dead load by identifying the amount of each construction material used in the roof. Identify the weight of each, using the American Society of Civil Engineers Publication 7-05 as a the nationally accepted source for weights of construction materials. Add the weight of equipment, if any, mounted on the roof. Divide the total roof weight by the area of the carport to express dead load in pounds per square foot.
Determine the live load. Consult the building code for your municipality or region for specific weights and requirements.
Add the dead load and the live load to obtain the total load, in pounds per square foot, of a carport roof.