Materials needed:

  • 2 x 10 or 2 x 8 Pressure Treated Wood
  • 4″ Wood screws

1. Measure the dimensions of the deck with a tape measure. Next, find the post locations. Start by marking where the corner and end posts will be on the deck. For the middle posts, determine if the side length is longer than the maximum span for your type of railing (6ft for picket railing, 5ft for glass railing). Add middle posts such that the sections will be equal, but will not exceed the maximum recommended railing length.

Example: (Picket Railing, Maximum Length = 6ft) 

5ft Side – No middle post required, 7ft Side – 1 middle post required.

Blocking 2 1 768x657 1

2. Next, cut sections of 2 x 8 to fit between the joists of the deck. Place them parallel (flat against) the rim joist and screw them in from the sides using wood screws.

Blocking detail revised



3. Once blocking is installed, deck boards can then be installed, so that the railing posts can be installed on top of the decking.

Cross Section blocking