I put two alchemy boilers on over the top of the other (because of an input mistake). I realise it afterward I had ignite both of them. They are slightly accessible, maybe by a pixel. But now, I can't get rid of any of them. The option of deconstruct or move don't show up.
I was able to destroy the double with an axe. But I do feel the game should stop some elements to be stack over one another, when you use -place-. I mean, it's logic when you want to put a candel over a table, but not a candle over a candle. I hope you have snapping in your built mode.