Measure the length of the lattice wall you plan to install. For the easiest installation, plan the wall to span between two posts along the deck railing so you can attach the lattice wall frame to the deck posts.
Measure from the top of the decking up to the height that you want the wall to reach. Look for tree branches, electric wires and similar items hanging near the fence when deciding how high to go with the lattice.
Sketch a picture of the lattice wall to help create your plans. You'll create a simple frame for the lattice from 1-inch-by-4-inch boards with the bottom of the frame resting on the decking and the side boards attached to the deck railing. This design creates the most stability for the lattice wall.
Cut two 1-inch-by-4-inch boards the same length as the height of your wall to create the side portion of the frame. Cut two more 1-by-4 boards equal to the width of the lattice wall to create the top and bottom of the frame.
Lay out the four pieces of lumber to create a rectangular shape for the frame. Attach the frame together using mending plates and flat corner braces. Predrill the holes first before screwing the plates and braces in place at each joint on the frame.
Cut the sheet of lattice slightly larger than the open middle portion of the frame, leaving enough extra lattice so you can attach it to the frame. Lay the lattice on the back side of the frame so the opening is completely covered. Predrill holes through the lattice and into the frame. Screw the lattice in place through these predrilled holes.
Position the frame on the deck against the railing. Drill pilot holes through the frame and into the railing with at least two holes on each side of the frame at both the top and bottom. Screw the frame into place using 3-inch decking screws.