Supports and Cave ins

[The PeePeePooPoo Man]

How do cave-ins work? how do i use supports and walls to stop cave-ins? how many and where in a room do i need to put supports to stop cave-ins?

All help is appreciated

[McFuzz]

Cave ins don't occur unless there's absolutely nothing supporting a roof at all.

For now.

You can support a 90x90x90 cube on a single wooden support. So as long as you're digging underground and not doing surface work or construction, you will likely never encounter one.

[koimeiji]

A cave-in will only occur to any unsupported tile or groups of tiles. (a tile is supported if it's connected to another in at least one cardinal direction; north, south, east, west, +z, -z)

You'll only ever encounter one (under normal circumstances) if you're channeling and aren't paying attention; especially if you're channeling multiple z-levels at once.

[The PeePeePooPoo Man]

Originally posted by Frank McFuzz:

Cave ins don't occur unless there's absolutely nothing supporting a roof at all.

For now.

You can support a 90x90x90 cube on a single wooden support. So as long as you're digging underground and not doing surface work or construction, you will likely never encounter one.

https://i.imgur.com/dts2kSh.png

All of those green tiles are where the ground level tiles have fallen and left open space. i dont know whether these are cave-ins or if they are i dont know why they are happening as some have happened to tiles directly next to supports. I have no clue what is happening.

[BlackSmokeDMax]

Originally posted by The PeePeePooPoo Man:

Originally posted by Frank McFuzz:

Cave ins don't occur unless there's absolutely nothing supporting a roof at all.

For now.

You can support a 90x90x90 cube on a single wooden support. So as long as you're digging underground and not doing surface work or construction, you will likely never encounter one.

http://store.steampowered.com

All of those green tiles are where the ground level tiles have fallen and left open space. i dont know whether these are cave-ins or if they are i dont know why they are happening as some have happened to tiles directly next to supports. I have no clue what is happening.

Surface holes are typically caused by digging under where a tree is one z level up and then later cutting that tree down. Think of it as the roots of the tree falling into your base after you've chopped the above ground portion of the tree.

[The PeePeePooPoo Man]

Originally posted by BlackSmokeDMax:

Originally posted by The PeePeePooPoo Man:

http://store.steampowered.com

All of those green tiles are where the ground level tiles have fallen and left open space. i dont know whether these are cave-ins or if they are i dont know why they are happening as some have happened to tiles directly next to supports. I have no clue what is happening.

Surface holes are typically caused by digging under where a tree is one z level up and then later cutting that tree down. Think of it as the roots of the tree falling into your base after you've chopped the above ground portion of the tree.

so i dont need all those support posts? also do i cut down the tree before digging under them to stop the holes?

[MaGicBush]

Originally posted by koimeiji:

A cave-in will only occur to any unsupported tile or groups of tiles. (a tile is supported if it's connected to another in at least one cardinal direction; north, south, east, west, +z, -z)

You'll only ever encounter one (under normal circumstances) if you're channeling and aren't paying attention; especially if you're channeling multiple z-levels at once.

I ran into one during construction. My dwarfs built a bunch of floor on a second z level before the walls, and down it went when I was trying to learn.

[McFuzz]

Okay, I see the problem.

They are tree holes. Your fort is one level beneath the surface; when you cut a tree with open air beneath it, it punches a hole in the tile because it removes the roots. I dunno if it's a bug or intended; I've always assumed intended.

To prevent this, you should usually build a few levels down, preferably in stone for smoothing and engraving purposes.

In your circumstance, you don't need supports, but you do need to put a floor tile on level above in the holes as they appear.