The water’s coming down so fast, it’s pooling on the roof. Your torch beam seems only to strike rain, and can barely illuminate what’s beyond that. There are long metal cases containing cables and ducting running along the roof, joining together the bigger pieces of equipment. These look easy to trip over and the way the wind is tugging at your clothes, you’re becoming less and less certain that this is a good idea.
You make one circuit of the concrete block that contains the top of the staircase and the lift machinery, then gratefully make it back to the door. You’re a bit damp now.