I was cleaning out my barn and there was a stack of about 10 old mattresses and 10 box springs that had been sitting uncovered for years and had bat and bird droppings all over them along with 4 or 5 recliners. since the garbage company wouldnt take them and they took up so much space, we really couldn't do anything else with them but burn them. there ended up being around 300lbs to 350lbs of shred left once it burned out. way more than i would have expected.