We have booked them to store the vast majority of our stuff for a couple of months while we temporarily move in with my mum (our new place is not ready). Most of our stuff is boxed up and most of our furniture is wooden. However, I am wondering what to do about our sofa and mattresses. Are the storage units clean? Can I just put the sofa and mattresses in there uncovered? Do I need something specail to protect them? Any ideas?