Twice a day for about 5 min.Murphy is one lucky dude! Do you have the 'shower' on a timer?
It's pressure treated but it's been 3 winters now it probably won't last much longer, I'll probably be building it again next year. I originally had it built on a platform with insulation from the groundand when I moved it this was the wood from the floor, even with a tarp over it all that time.Nice! is the plywood sealed or treated at all?