Hackers Help: Stacked BILLY bookshelves?

stacked Billy bookshelves

Has anyone stacked BILLY bookshelves one on top of another? I’m thinking of laying them down on their side and stacking one on top of the other (I only have 2).

stacked Billy bookshelves
BILLY | IKEA.com

I just don’t know if the bottom shelf will support the weight of another BILLY bookshelf being laid on top of it as well as whatever I put in the shelves and a 47 inch TV on top of the whole thing?

Has anyone tried this with success?

Thanks very much,

Sandra