Roof Weight Rating

When it comes to estimating the weight of an existing roof field verification of the in place construction is necessary.

Roof weight rating.

Static load rating when the vehicle is stationary. Driving either on highways or around town will be fine with this type of dynamic load. 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. 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. Wind loads depend on wind speed and can vary as widely as the snow. A clay tiled roof may have a dead load. The load rating is the amount of weight the vehicle manufacturer says the roof can handle.

This is all of the natural stresses imposed upon a roof such as snow loads rain loads and wind loads. The load increases with the use of heavier roofing material. 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. Though in many cases the racks can withstand greater loads to avoid damage to your vehicle it is important to understand your vehicles limitations.