Will one central pillar / wall support a 20x20 room?

[a three-colored carp]

I'm trying to build a mountain base and don't want a cave-in. I doubt I'll build a room that's 20x20 but would that work?

[Jack]

Yes.
Pillars and walls support 6 tiles in any direction (7 counting the tile directly above them) so with a pillar in the middle this will be 25 tiles (not including the walls)

[gimmethegepgun]

A good trick to use is, if you select the pillar for construction, and hover it over a tile, if there isn't anything that supports a roof within the indicated area, then the tile that you're hovering over with the pillar isn't supported.

[- BusterZlista -]

use 11x11 always, it is the perfect room size

[Phénomènes Mystiques]

Originally posted by - BusterZlista -:

use 11x11 always, it is the perfect room size

I went with the 30x30 design.