How to Install Deck Stair Stringers

Preparation

• 1

  Measure and mark vertical lines at the positions where the stringers will be attached to the face of the end joist, using a measuring tape and pencil. Use a carpenter's square to ensure the lines are level and space the marks evenly apart, with no more than 16 inches between each pair.

• 2

  Position two stringers against the joist, centering each one over a pencil mark and across from each other.

• 3

  Measure the distance between the stringers along the joist, using a measuring tape.

• 4

  Cut two blocking pieces, from boards that are equal to the width of the joist, to fit between the top and bottom of each pair of stringers, using a power saw.

• 5

  Continue to position stringers, centering them on the remaining pencil marks, and cut two blocking pieces to fit between each remaining pair. Remove all but the first pair of stringers before beginning installation.

Installation

• 6

  Position a piece of blocking between the tops of the first pair of stringers, against the joist. Secure the blocking piece in place with wood clamps.

• 7

  Drill holes through the blocking piece, staggering them as you work along its length, using a power drill and drill bit.

• 8

  Ensure that the stringers are square, using the carpenter's square, and insert a wood screw into each hole. Tighten them firmly to secure the blocking to the joist, using the power drill and a Phillips screwdriver bit. Remove the clamps.

• 9

  Drill several holes through the outside of each stringer, along the lengths where they rest against the blocking.

• 10

  Position a piece of blocking between the first pair of stringers where they sit on the footing or landing. Ensure that it fits snugly between the stringers and align its front edge with the front edges of the stringers.

• 11

  Drill holes through the bottom blocking piece, staggering them as you work along its length.

• 12

  Ensure that the stringers are square, using the carpenter's square, and insert a wood screw into each hole, tightening them firmly with a power drill and Phillips screwdriver bit. Insert masonry nails if you are securing the blocking to concrete and pound them in place with a hammer.

• 13

  Drill several holes through the outside of each stringer along their length where they rest against the blocking.

• 14

  Continue to attach blocking pieces and stringers in place in the same manner described until you reach the end of the width of the stairway.