I am having some issues building a spiral staircase. I followed the steps in the post that has 25 pictures and it appears that what I have at the end is exactly the same. However the last part of the stair is much higher than the floor and the step behind it is too low. Also there is a gap where I am standing but the goza do not raise high enough to reach the floor. I am not sure what I did wrong. I didn't build it near an outside wall..could that be causing a problem? I watched an old video of someone building an L-shaped staircase and I noticed he did some of the work on the second floor. I did all of this staircase on the first floor. Can anyone help?