We have a fairly large loft space in our late Victorian end of terrace house, with a floor that has been handily boarded over by the previous owners. I have four boxes of spare bathroom tiles that I'd ideally like to store up there, but they're quite heavy (about two stone per box?) and I'm worried about the effect the weight could have on the joists.
Is it safe to store heavy items in a loft or is it really only for very light stuff (like empty suitcases, Christmas baubles etc)?