Measure the area the lattice needs to fit. For garden backdrops, a whole 4-by-8-foot sheet can be stood on end to give a tall focal point for the planting area or other features. For a porch or patio, the pieces need to be cut to fit the spaces they will be attached to.
Measure lengths of 1-by-4-foot treated boards for the frame on the lattice. For this example a full 4-by-8-foot lattice sheet is framed. Cut two pieces of 1-by-4 into 40-inch lengths. Lay them parallel on the work surface or ground, and align two 8-foot pieces of 1-by-4 outside of them. Square up the four pieces so the shorter ones create ends between the longer ones, with the corners and outside edges squared.
Attach a flat mending plate across the joint in one corner, 1/2 inch in from the outside edge so it spans the seam between the two boards. Screw in place using the flat head wood screws.
Add a flat corner brace 1/2 inch in from the bottom or inside edge of the boards, spanning the joint across the corner. Screw in place as with the other plate. Repeat for each corner.
Lay the lattice sheet over the frame. Align it so that it sits evenly on the frame and none of the ends are protruding beyond the outside edges of the frame wood.
Add a screw to the end of each lattice strip that extends out onto the frame from the main panel. Screw 1/4 inch in from the end of the lattice strip, down into the wood frame. Screw the ends all the way around.
Stand the frame and, using the L-bracket or angle ties, attach it to the post or surface in front of which you want the lattice to sit. Frames hung around the bottom of a high porch can be attached with hinges to allow for raising them to gain access to beneath the porch.