Stair Types    
  Open Riser stairs (left) are easy to build. They require only a cit stringer and treads. Seal the cut portions of the stringers, which are prone to rot, before you fasten the treads. Open stairs can also be built with cleated stringers.

Closed Riser Stairs (right) take a bit more work to build, but many people prefer this more formal look.
Cleated Stringers    
  Uncut stringers with metal tread cleats resist rot better because they have less exposed end grain. To install cleats, bolt them just below the tread lines. Use three one inch lag screws for each cleat.
Measuring Stair Rise    
 

Outdoor stairs often descend to an uneven grade. To measure the height from the stair landing to the deck height, use a level on top of a lond, straight board.
     
Calculating Rise & Run    
Rule of Thumb: The sum of a riser (7 to 8 inches) and a tread (9 to 10 inches) should be about 17 to 18 inches.   The Clearest way to think about stair dmart/layout it to visualize the steps as a series of small triangles divided from a large one. The rise is the height of the stairs from the top of the deck to the ground. The run is the distance from the face of the deck to the front edge of the last riser. Remember that it's often possible to add or subtract one step from a long flight of stairs for a more comfortable dmart/layout.
     
Laying Out Rise & Run    
  Once you calculate the rise and run, you can lay out a 2"x12" stringer.Lay the framing square so that it's corner overlaps the board. Line up the rise and run to mark the stair cutout. Slide the square to the edge of the step you've marked and move down along the stringer until all of the steps are marked. To mark the stringer's bottom, draw a line parallel to the last tread at the bottom of the stringer.
     
Cutting Stringers    
  You can make the stringer cutouts with a circular saw, but to finish the inside corner you will need a hand saw or jig saw.If you're using wide boards for treads, it's a good idea to angle the tread cuts slightly to make sure they drain from the back and front.
     
     
Attaching Stringers    
Cleated Stringer to the Deck    
  Use a framing anchor to secure the top of the stringer to the deck frame. Make sure that the stringers are level at each step.
     
Cut Stringer to the Deck    
  To hold a cut stringer securely to the joist framing, it should extend under the rim joist and be face-nailed to the joists or blocking. You'll probably have to add blocking unless your joists run parallel to, and line up with you stringers. You can also use joist hangers notched into the stringer to carry the load. But that arrangement is weaker.
     
Stringer to a Post    
  You can bolt the stringer through a post near the bottom. This eliminates the need for a footing.
     
Stringer to a Footing    
  To increase stability pour a bottom step with a 2x4 thrust block (held with J-bolts) to hold the stringer. In some areas you may be required to pour a step six inches above grade like this one. It's always a good idea to check your local building code.