If you want that deck to be sturdy, then attaching your stair stringers to the deck is really important to get right. The stairs will be at least 36 inches wide, and using three stringers is the strongest way to build your stairs. You have to cut and the stringers so they wedge behind a rim joist. If a floor joist isn't near, then, you will have to block wood in, so you have something to attach
. the stringers to. An ideal way to attach the stringers is to screw a board right where they will install at, so they have something to rest on. There's pictures, and detailed instructions at http://www.bestdecksite.com/deck_map/deck_map_stair_stringer.htm.
