How many exits do you provide signs for? Just the primary route? I work mainly I schools and have been told to only put signs on the primary routes, however if this route is blocked I don't know how a visitor would know the secondary route. But then if I sign a secondary route this may be confusing! There are normally plans available, but these only show the primary routes, however I'm not sure if anyone would read them in an emergency. I have checked BS9999 and Building regs B, but can't seem to find it.