Question in a nutshell: How long would it take an intense fire started by supernatural means to spread through an old building around the size of the Biltmore Estate?
Googled: fire spreading in brick buildings, how fast does fire spread in a building
The climax of my story occurs when a character sets fire (using supernatural means, so the fire is very powerful) to a huge boarding school. It is three stories, and about the scale of the Biltmore House. The layout is extremely random - think Winchester Mystery House. The building is mostly made of brick, but has been added on to randomly over the last 80 years, so there are portions that are old and parts that are newer.
The fire is started on the first floor (Point A, marked by the crappy fire). What would be a good estimate of the amount of time it would take the fire to reach Point B (marked by the star, and accidentally by the dropper) on the third floor? It would be burning it's way through a lot of old wood, mainly, and the exterior is brick so it's just spreading indoors.
Edited to add: During the course of the fire, there is no attempt to put it out. The school is high security and in the middle of nowhere, so no firefighters will be alerted. There is no sprinkler system installed. So this fire will run its course until it burns out on its own.
I with I could tell you the exact distance between the points, but I'm horrible at visualizing yards, and couldn't find a good representation online. That's why I included this picture of the Biltmore.
Also, how fast do you think the smoke would get to the fourth floor? There is a character trapped at Point B, and I have no idea how much smoke would have made it up to that corridor by the time his rescuer finds him (entering from the opposite side of the building from the fire). The building is not extremely open - lots of twisting and turning corridors, and most of the staircases in the part of the building with the fire are behind doors. So would there even be any smoke up there after about 20 minutes? Or would the fire have already reached Point B by that time?
I'm sorry this question is so complicated, and probably asking too much. But I'm stumped, and this is a very important scene. I want to make it as real as possible, but I know nothing about this topic. Ask any questions you need to, and I'll be happy to clarify.