Ask most building owners what protects their property from fire and they'll point to the sprinklers, the alarms, the extinguishers on the wall. All vital, but all active fire protection. They detect or respond to fire after it's already started. There's another layer of protection built into the very structure of your building. Most people never see it, rarely think about it, and almost never maintain it. It's called passive fire protection and it may be the single most impor