Fences on top of fences

I wanted to build a portcullis for my castle by using picket fences on top of each other, but I found out the game doesn’t let you do this. I tried instead to build a wall so that I could place the top row of fences, and then I would delete the wall and build a new one for the next row down, repeating until it was done. Unfortunately, the fences fell as items when i deleted the wall, so that won’t work either.
I have already built half of the castle (using around 400 stone and waiting for around 12 hours to have it built) and I had designed the gatehouse with this idea in mind. I guess I should do a small mock up before ordering the whole build next time. Anyone know of an exploit/glitch/workaround I can use to try to make this work?

Did you waited for them to place the bottom row before trying to add the row above?

Did you try moving an already placed fence on top of the bottom row? (I hear this a lot, it works when moving an already placed item)


Placing the fence and then ordering it to be moved on top of another worked. Thanks.