I ordered a headboard, which has now arrived. It’s 5.5cm thick, which didn’t sound like much, but now that it’s here I realise that’s actually quite thick. It will either have to go behind the mattress, which would leave the mattress sticking off the end of the bed - not a good option at all - or above the mattress, which would obviously shorten the space on the mattress. I’m wondering whether thinner headboards exist, or is this just what headboards are like?!