to clear a room you mine this leaves a floor and ceiling.
For stairs up/down stairs allow you to go up or down from the layer they are on. This requires stairs on the layer you are moving to as well. Down stairs go only down up stairs go only up.
To remove the floor from a layer you would use channel, this leaves a ramp on the lower layer that allows movement up and down. These can be removed.
@lightnsfw thank you!! So far I’m at the tutorial stage and couldn’t get the stairs placed or any digging done form the mining menu. I tried several new games to see if that was the problem but I think it user error.
@lightnsfw thanks I’ll give that a more thorough look. I’ve been following it but it seems to conflict with the other info I have seen online. For example I am near my wagon, click m, then t, select the tile for a stair, hit e to go down a level, select that tile and then nothing. I built one randomly this way on a cliff but no idea how I did it and it goes no where. I was able to construct a few stairs with the construction menu and a similar workflow but those don’t seem usable either.
to mine a stairwell you need to press m, t then select the square and move up or down however many layers you want to go and then click again, that will designate those blocks to be cut into stairs (it will show the stairs but they will not actually be stairs there until a dwarf does the mining). This will designate a down stair at the top layer you select and an up stair at the bottom with up/down stairs in between. you need to have a dwarf assigned to mining to do this.
You can build them in the construction menu as well but that requires you to have already mined out the area you are building in so it takes longer.
If the above doesn’t work post a screen shot of what yours looks like.