Preparation

• Measure the area where you want to install the trellis. Make a drawing outlining the trellis size and placement and divide the area into even sections of trellis.
  
  Purchase ready-made lattice panels at any local home center. They come in several varieties; the two best options for this project are white vinyl or quarter-inch thick treated wood. You will also need enough 2 by 4 inch treated lumber to build frames for your lattice, treated 4 by 4 posts to support the ends and treated 1 by 2 lumber for the inside stop to hold the lattice in place.
  
  Lattice panels come in varying sizes, depending on the manufacturer. Typical sizes are 2 by 4 feet and 4 by 8 feet. A trip to find out what sizes are available from your local retailers before completing your plan would be beneficial. If you choose white vinyl, buy enough white semigloss latex to paint your framing to match.
  
  

Building the Trellis Panels

• Build a four-sided frame for each panel. Let's take a 30 by 30 inch panel of lattice, for example. You will need two pieces of 2 by 4 treated lumber 33¼ inches long and 2 that are 30¼ inches long. Set the 2 by 4s on a sturdy level surface on edge and lay them out to form a square 33¼ by 33¼ inches. The long pieces overlap the shorter on opposite sides of the square. Attach the joints with 3-inch treated deck screws.
  
  Build a smaller square of 1 by 2 lumber to fit inside this frame snugly. Cut two pieces of 1 by 2 inch treated lumber 33¼ inches long and two that are 31¾ inches long. Build a square 30¼ inches across with the 1 by 2s standing on edge. Overlap the longer pieces and screw them together with 1¼-inch treated deck screws.
  
  Set the 1 by 2 frame inside the 2 by 4 frame. It should fit snugly. Tap or press it flush with the back face of the 2 by 4 frame. Attach the 1 by 2 frame with 1¼ inch screws. Set the lattice panel inside the 2 by 4 frame and press it down until it rests on the 1 by 2 frame. Build a second 1 by 2 frame and set it in on top of the lattice, picture frame mat style, to hold the panel in place.
  
  

Installing the Trellis

• Install posts at the ends of each section of trellis and any corners. Use 4 by 4 post brackets on the patio to install the posts. Use Tapcon-style concrete anchors to install the brackets and 3-inch screws to attach the posts to them. Cut the posts to the appropriate height. Install the trellis panels between posts with 3-inch screws. L brackets can be used to reinforce the joints if the trellis seems a bit shaky.
  
  Posts can also be set off the edge of the patio in footings. Dig your post hole at least one fourth of the above-ground height and add enough concrete to fill the hole to 2 inches below ground level. Pack the rest with dirt.