Tire storage

Currently have Perelli snow tires on my Volvo XC70, will be putting on “summer” tires this week. What is the best way to store the snows or more importantly how should they not be stored (as far as storage space/area the best for me is above my garage in the storage/attic area)… … just have a bit of concern as i remember that the Firestone debacle may have been traced back to storage issues (?).