March 11, 2009
DIY Garden Trellis
Whether your garden consists of a few pots on a city balcony or a quarter-acre in the suburbs, it likely has a spot that would accommodate a classic trellis. Covered with climbing plants like ivy, clematis or morning glory, this latticework trellis can add lush colour to a treeless space, disguise an unattractive wall or fence, or act as a privacy screen on a deck. This handsome structure is a sturdier version of what’s available at most nurseries and garden centres. If you’ve got a spare weekend, all you’ll need to recreate this elegant design are basic woodworking tools, a few lengths of cedar and a little patience for precision measuring and cutting.
Materials and Tools
- 4′ of 2″ x 6″ cedar (for curved top)
- 14′ of 2″ x 2″ cedar (for frame)
- 36′ of 5/16″ x 1-1/2″ cedar lath (for latticework)
- Decorative wood finial
- 1/2″ nails
- 1/2″ brads and 3/4″ brads
- 8 2″ L-brackets
- Heavy cardboard
- Mitre box
- Hammer or nail press
- Waterproof wood glue
- Wood filler
- Set square
- Paint or stain (optional)
What it Cost
4′ of 2″ x 6″ cedar $23
14′ of 2″ x 2″ cedar $26
36′ of 5/16″ x 1-1/2″ cedar lath $28
Screws, nails, brads, brackets $15
Wood glue and filler $9
2 L paint or stain (optional) $33
Step 1: Make template for trellis top
Enlarge Diagram 1 on a photocopier. Create a template for the curved trellis top by tracing this enlarged shape onto heavy cardboard. (You only need to make a template for one half of the top since the second half is a mirror image.)
Step 2: Cut curved top pieces
To save wood, each side of the curved top is made of two pieces of cedar screwed together. Lay the template on a piece of 2″ x 6″ cedar as close to the edge as possible, and trace the outline of one half of it. Mark off the second half on the same piece of cedar, fitting it just above the first so that both can be cut from a 2′ piece of cedar (see Photo 1). Repeat for second side of curved top. Cut out, using a jigsaw.
Step 3: Join curved top pieces
Apply waterproof wood glue to the ends of the two curved pieces, and screw them together with 1-1/2″ #6 wood screws to create one side of the curved top (see Photo 2). Repeat for other side.
Step 4: Assemble top of trellis
To create the curved top of the trellis, lay the two curved sides on a flat surface, so their top ends meet. Apply waterproof wood glue and screw them together, using 1-1/2″ #6 wood screws, screwing from the side (see Photo 3). If edges are not completely flush, fill with wood filler and sand.
Step 5: Cut side and bottom pieces
From 2″ x 2″ cedar, cut two pieces to 51″ long (sides of trellis) and one piece to 48″ long (bottom of trellis).
Step 6: Join sides to bottom
Mortise the corners where the side and bottom pieces will be joined. To do this, on one end of each side piece and both ends of the bottom piece, draw a line across the wood, 1-1/2″ in from the end. Make another line on the end, at half the depth. Be sure to measure carefully. Using a mitre box, saw carefully through the wood at the 1-1/2″ mark, stopping at the line that indicates half the depth. Then saw in from the end along the half-depth mark, so that you have cut away a square half the thickness of the wood. Lay the pieces together so that the cutout portions of the side pieces rest on the cutout portions of the bottom piece, making a neat joint. Attach with wood glue and screw together using 1″ #6 screws (see Photo 4). Fill any cracks in the joints with wood filler. Let dry. Sand smooth.
Step 7: Join sides to top
Mortise the corners where the side pieces will join the curved top. To do this, lay the curved top on the ends of the side pieces. With a pencil, mark the angle of the top across the top of each side piece and another halfway down on the end, as in Step 6. On the curved pieces, make a mark 1-1/2″ in from the end, and another halfway down on the ends. Cut, glue and screw together as in Step 6, then fill and sand.
Step 8: Complete frame
Cut a piece of 5/16″ x 1-1/2″ lath to fit along the inside edge of the bottom of the frame. With the frame lying on a flat surface, glue, clamp and nail the lath to the frame so that it protrudes from one side of the frame (what will be the front) by about 1/4″ and forms a “lip” or ledge on what will be the back of the frame, onto which the lath will be nailed to form the latticework (see Diagram 2). Cut 2 pieces of lath to fit along the inside edges of the curved top. To attach them, apply wood glue, then gently bend them along the curves, clamping to hold in place (see Photo 5). Nail on. Cut 2 pieces of lath to fit along the inside edges of the sides of the frame. Glue, clamp and nail in place. Allow to dry according to glue package directions.
Step 9: Check frame measurements
Before adding the crisscrossed lath, check that the frame is square by measuring each corner with a set square, and measuring diagonally from outside corner to outside corner. The two diagonal measurements should be equal. The frame will still have some flexibility at this point; if it isn’t square, shift it until it is square, then use clamps to secure it in place on your work surface if possible.
Step 10: Cut horizontal slats
For the horizontal slats, cut 5 pieces of lath to 45″ long, one to 23″ long and one to 11″ long. Lay one 45″ piece across the bottom of the frame and mark the locations of the vertical pieces that will cross it using the measurements in Diagram 1. Mark the lath locations across the bottom of the frame as well.
Step 11: Cut vertical slats
For the vertical slats, cut one piece of lath to 76″, two to 65-3/4″, two to 58-1/4″ and two to 53-1/4″.
Step 12: Mark slat locations
Lay the 76″ piece of lath along one side of the frame, and mark the locations of the horizontal pieces that will cross it using the measurements in Diagram 1; mark these measurements along the side of the frame as well. To mark the locations of the top two horizontal pieces that lie across the curved top, extend a T-square or a strip of lath from the 76″ vertical piece to the curved top, and mark.
Step 13: Install horizontal pieces
Place one of the 45″ horizontal pieces across the centre of the frame, and the four other 45″ horizontal pieces on the frame as per the markings you made in Step 12. The horizontal pieces should fit neatly just inside the 2″ x 2″ cedar, resting on the lip created by the trim installed in Step 8. Apply a dab of wood glue to both surfaces where the lath sits on the lip, then nail on with 1/2″ nails. Lay the 23″ piece and the 11″ piece at the appropriate markings and, with a pencil, mark on them the angle of the curved piece. Saw their ends off so they sit neatly inside the 2″ x 2″ cedar.
Step 14: Install vertical pieces
Lay the seven vertical lath pieces across the horizontal pieces, so they line up with the marks you made (on the centre piece and across the bottom of the frame) in Step 10. They should overlap the bottom of the frame by about 1/2″. With a pencil, mark on them the angle where they meet the curved top and saw their ends off so they don’t protrude beyond the edges of the curve.
Step 15: Reinforce lattice joints
Apply a dab of wood glue to the ends of all the vertical pieces and to each spot where vertical and horizontal pieces cross. Nail on the ends of all the vertical pieces using 3/4″ brads. Nail together all the joints using 1/2″ brads, starting at the centre and working outward. Slide a scrap of wood under each joint before you nail it, to avoid breaking the lath (see Photo 7; note: builder is using a nail press but a small hammer will work just as well).
Step 16: Attach finial
To apply the finial, from a scrap piece of lath, cut a small block slightly larger than the point at the top of the frame. Sand this piece smooth. Countersink a 1-1/2″ wood screw into it. Glue and nail the block to the top of the frame so the point of the screw faces upward. Screw the finial onto the protruding screw.
Step 17: Sand and finish
Sand the trellis lightly. Paint or stain it, or leave natural. Left untreated, the cedar will weather to an attractive silvery-grey colour.
Step 18: Hang trellis
Attach the trellis to a wall or fence with eight 2″ L-brackets (four on each side) screwed into the sides of the frame, evenly spaced.