I have to move soon (my current property company used to be the best but is now the worst and I can't take it anymore. Long story.) I want a 2 br, so I have an extra room for books & yarn. I want to get an air mattress so my brother can visit, but he's not in great shape so I want an elevated one. How on earth do you get sheets on those? Do they even make fitted sheets that are 18 or more inches deep?