How to Space Joists When Using Trex

Spacing the Brackets

• 1

  Measure along the rim joist, perpendicular to the main support joists and mark the board every 12 inches.

  Using a rafter square, transfer this mark and draw a line in that position across the face of the rim joist, vertically. Start from the same end of the deck and mark the opposite rim joist in the same way.

• 2

  From each of these marks, measure back towards the end you first measured from, and draw a second line with the square to indicate the edge of the joist. Mark through the original boards with a diagonal stroke to avoid confusion as to which line is which.

• 3

  Fit a metal joist hanger with one edge aligned with the second line in each of these positions.

  Align the left edge if you measured from the left end of the rim joist and the right edge if you measured from the right. Drive one 1 5/8 inch treated decking screw through each hole in the bracket tab on that side of the hanger to secure it.

Installing Joists

• 4

  Fit your joists into the hangers with one narrow edge down in the three sided seat of the hanger.

  Fit one joist into each pair of hangers between the two joists you marked.

• 5

  Fold the loose side of each joist hanger up to press the joist snugly against the side you first attached.

  Add screws in the tab on this side of the hanger, one in each hole.

• 6

  Drive one screw through each of the angled eyes on the sides of the joist hanger on each joist, so that they angle through the joist into the rim joist in each position.