Solar Panel Load On Roof

In areas where there is snow this live load is increased to compensate for the snow that may accumulate on the roof.

Solar panel load on roof. For example the weight per square footing for asphalt shingle weight per 100sq ft lbs range is 190 250. When wind blows across a roof with solar panels it passes through the small space that typically exists between the panels and the roof or between your panels and the ground in the case of ground mounted systems causing a large amount of uplift to the panels. Asce in their minimum design loads standards book. Wind loads on every building or structure shall be determined in accordance with chapter.

For example asce 7 16 now clearly states that the weight of solar panels and their support are to be considered as dead loads 1 roof live loads need not be applied to areas covered by solar panels under a certain spacing or height 2 and seismic design is based on already established principles in section 13 3 for non structural component. The solar panel support system must be arranged to ensure that loads from solar panels including snow on panels and wind uplift are distributed evenly to roof framing members. 1608 1 design snow loads shall be determined in accordance with chapter 7 of asce 7 but the design roof load shall not be less than that determined by section 1607. Distribution of solar panel weight.

The weight per 100sq ft kg range is 85 110. Therefore a typical roof with 24 inch rafter spacing and rafters that weight 2 plf would have a dead load of 10 x 24 12 2 22 plf before the solar equipment was added. For a 16 foot rafter this then results in a 352 lbs. 1609 1 1 determination of wind loads.

Design loads the following design loads must be considered for structural analysis. While asce doesn t. The point load for different mounting or fastening locations have to be distributed in such a way that it reduces the overall load on the roof and minimize roof leaks. Structural engineers use the solar panel roof load calculator to come up with the correct load capacity of the roof material.

Since you cannot walk on top of the solar panels it has been agreed by the permitting agencies to include the weight of the solar panels in this live load. Just a heads up that the weight load of the panels may be small compared to the upward force on the panels in some wind conditions. The load bearing capacity of a roof should be adequate to support not only the roof cladding materials such as tiles or shingles but also objects that sit on top of the roof like antennae satellite dishes air conditioning units solar hot water systems and solar photovoltaic panels. You have to design your mounting to handle both force directions.

With 10 pounds per square foot as a minimum amount accounted for and 2. Sunnyboy 3000 us 18 bp solar 175b panels.