S-1 and S-2 separations

[retire09]

There is no separation required between an S-1 and a B occupancy but a 2 HR separation is required between a B and an S-2.

This appears to be backwards since the S-1 is a higher fire hazard than the S-2.

Can anyone explain the logic in this?

 

[mtlogcabin]

You are protecting the S-2 from the higher "B" occupancy fire hazard

 

[BayPointArchitect]

It is my custom to bump up the S-2 occupancy (noncombustible stuff being stored) to a S-1 occupancy (combustible stuff being stored) so as to eliminate the need for separation. I see nothing wrong with that.