How do I stop mountain roofs from collapsing?

[Lycon]

I had colonists die because the roof collapsed. How do I know its about to collaps? Any way to remove the roof? How do I deal with this if I want to cut out a mountains?

[Qiox]

The widest gap that will not collapse is 12 tiles. So a 12 x 12 open space is fine. Or put another way, any roof spot must be at most 6 tiles away from a wall or door. Anything bigger under a mountain and you have to leave single tile support to hold it up.

[corisai]

Originally posted by Lycon:

How do I deal with this if I want to cut out a mountains?

https://steamcommunity.com/sharedfiles/filedetails/?id=1499236003

[Trickst3r83]

You can decrease the maximum damage if you mine it slowly and also slowly remove the roof of the mountain, but it will get to a point that it will still collapse, but not as much if you didn't removed the outter part roof of the mountain

[Henry of Skalitz]

Place walls to act as your supports. Problem solved

[Preechr]

To remove a mountain roof, you'll need to add a mod. There are several mods out there that let you do that in different ways. The one that @corisai linked requires you to research the ability to do it, which is fairly balanced. If your goal is to completely remove a mountain, you'll need a mod like that to help you do it.

[di eshor ribly]

Originally posted by Preechr:

To remove a mountain roof, you'll need to add a mod. There are several mods out there that let you do that in different ways. The one that @corisai linked requires you to research the ability to do it, which is fairly balanced. If your goal is to completely remove a mountain, you'll need a mod like that to help you do it.

The terraforming bits require research and materials, but removal of thick roofs (aka, mountains) is unlocked from the beginning. I usually end up clear-cutting my entire map to make a centralized fortress with a moat.