Getting onto the roof of Large Shirogane Castle Walls

[nranola]

I was able to place the items correctly once, but I had to move the elevator to a different spot, and now I'm having a hard time. >< Is there a way to tell if I'm getting close to doing it right? I've placed the wall and the stump and now I'm adjusting the arc. Right now I'm able to jump but it just blocks off the top and I stay in place - is that a good sign?

EDIT: I was able to replicate it at the same spot as before. I'm guessing this glitch only works in certain parts of certain houses?