Roof Weight Rating

Though in many cases the racks can withstand greater loads to avoid damage to your vehicle it is important to understand your vehicles limitations.

Roof weight rating.

The dead load of a typical asphalt shingled wood framed roof is about 15 pounds per square foot. 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. The load increases with the use of heavier roofing material. When you have the roof racks to support your rooftop tent fitted they will be placed around 30 inches apart.

When it comes to estimating the weight of an existing roof field verification of the in place construction is necessary. Driving either on highways or around town will be fine with this type of dynamic load. Static load rating when the vehicle is stationary. 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.

This is highly regional as weights of snow for example range from 10 to 300 pounds per square foot based on moisture and volume of the snow. A clay tiled roof may have a dead load. Wind loads depend on wind speed and can vary as widely as the snow. This is all of the natural stresses imposed upon a roof such as snow loads rain loads and wind loads.