RAM SS - overlapping portions of snow loads

Question

How is the distribution of loads to roof members considered when the loads shown are overlapping. See pic below. Since these are drift loads and are tapering down to a specified value, am not sure what load is being considered at the interface of 2 overlapping loads?

Seth Guthrie · Answer

The rule to remember in RAM SS is "only the top load counts". The highlighted polygon S4 is fairly complex, but if the red M1 and M2 values are equal (say the high point) and the red M3 is the low point, then the blue M3 location will be roughly half way between those magnitudes and applied to the beams within that highlighted area. The other load area can have the same or completely different magnitudes.