August 6th, 2018

Collapsing the great hall of a medieval castle

Setting: A version of Medieval Europe with fantasy elements; the great hall of a castle under attack.

Search terms: building collapse disaster, medieval roof collapse, roof collapse warning signs, how to collapse a roof, goodrich castle reconstruction

Hi. I'm writing a story that is part time travel, part fantasy elements. Currently working on a scene where a castle has been attacked and taken by an invading force.
I've used the floor plans of Goodrich castle for a reference, and the entire fight takes place in the great hall - dimensions of about 20 m by 9 m, not certain what the ceiling height is.

My scene protagonist, a bowman turned blacksmith, is facing off against a fighter with superhuman strength and ability to shrug off wounds that should be mortal. Unable to take him out by conventional means, my protagonist intends to collapse the roof on them both.

I'm looking for a way to intentionally cause this roof collapse, in a way that can be set up beforehand in the space of a couple hours and triggered at a distance, by targeting or weakening the structural elements of the building. So far, most of what I've found have been examples of historic building collapse after an earthquake or poor building.

Is there a way to do this without involving gunpowder?
And can someone tell me what the stages of the roof collapse would look like from the inside?

Hope I get the tags working right. And the format. This is my first time posting here. Thanks everyone!