Roof Weight Rating

There are 3 types of load rating and the cargo rating.

Roof weight rating. The dead load of a typical asphalt shingled wood framed roof is about 15 pounds per square foot. This is all of the natural stresses imposed upon a roof such as snow loads rain loads and wind loads. A clay tiled roof may have a dead load. Driving either on highways or around town will be fine with this type of dynamic load.

The load increases with the use of heavier roofing material. Wind loads depend on wind speed and can vary as widely as the snow. When it comes to estimating the weight of an existing roof field verification of the in place construction is necessary. Asphalt shingle or asphalt fiberglass composite shingle 2 7 lbm ft2 13 2 kg m2 metal roofing aluminum or steel panel sheet or shingle 1 2 lbm ft2 5 9 kg m2 terne plate copper bearing steel sheet 0 7 lbm ft2 3 4 kg m2 wood shingle or shake 2 4 lbm ft2 11 7 kg m2 zinc roofing 1 6 lbm ft2 7 8 kg m2.

When you have the roof racks to support your rooftop tent fitted they will be placed around 30 inches apart. The load rating is the amount of weight the vehicle manufacturer says the roof can handle. Check the racks have a weight rating of 125 lbs or more as their dynamic load which will then be at least be equal to or greater than the weight of the rooftop tent. Though in many cases the racks can withstand greater loads to avoid damage to your vehicle it is important to understand your vehicles limitations.