Proper stair stringer installation Stair stringers need to be installed low enough to create 3 full step to reach the top _ of the deck, Additional framing may be required to support the weatherstripping in the picture to the left. Refer to the “How o Build Decks” book for imper detailed instructions. Stair stringers not properly installed will result in the stair and deck railings being different heights, as shown'in the:picture to the right.