by Tim Johnson
Make any climbing plant happy with this 6′ tall, free-standing trellis. We used dadoes, glue and screws to fasten the slats because trellises take a beating each year when you tear off the old vines. We built our trellis from cypress, one of the longest-lasting outdoor woods. Ours was recycled from old water tanks and cost about $175. White oak, at $60, would also be a good choice.
Marking the legs for the dadoes can be confusing, but if you follow our marking procedures (2a-2d), you can’t mess up. Even with our easy-to-make jigs, routing 68 dadoes is noisy, dusty and tedious (Fig. B and 4a). But once they’re done, the dadoes make assembly foolproof. There’s only one angle to remember: Everything slopes 6°.
You’ll need an angled template, made with the miter gauge on your tablesaw, to make the dadoing jigs. You’ll also need a router with a straight bit to cut the dadoes,
and a drill with a slotted tip for all the screws. We used a jointer and planer to mill our parts to thickness, but they could also be ripped to size on a tablesaw. The slats are thin, so be sure to use a push stick.
How to Build It
2. Mark the leg dadoes (2a-2d). The sides of the trellis are tapered, so the dadoes are angled.
3. Cut an 84° angled template, about 10″ long and at least 4″ wide. Use it to set the fence angle on the dadoing jigs (Fig. B).
4. Dado the legs (4a). One jig will slope the right direction for the 3/16″ deep dadoes on one side of each leg. The mirrorimage jig will be correct for the other side.
5. Mill slat material to thickness and rip it into lengths, slightly oversize in width. Then plane (or rip) the slats to fit the leg dadoes.
6. Cut the bottom and top slats (B through E) for all four sides to length, with a 6° bevel on both ends. You can cut the slats to length in pairs because opposite sides of the trellis are the same.
7. Frame the front and back faces of the trellis (7a). Align the beveled ends of the slats with the edges of the legs and drill pilot holes. Then drill out the holes in the slats so the screws slip through. Apply glue and assemble.
8. Cut the internal slats (F) to fit, and fasten them, following the procedures in Steps 6 and 7.
9. Stand the assembled front and back faces back-to-back in an “A,” and assemble the sides, following Steps 7 and 8.
10. With a handsaw, square off the legs at the top of the trellis.
11. Bandsaw the spire (Part G, Fig. C). Lay out the pattern on two adjacent faces of a glued-up blank. Make the blank a foot long to keep your fingers a safe distance from the blade. After cutting the first two sides of the pyramid, tape the offcuts back onto the blank. Rotate the blank 90° and cut the other two sides of the pyramid. Cut the second set of tapers the same way. After sanding, cut the spire from the blank.
12. Glue and screw retaining blocks (H) to the bottom of the spire, then soak it in preservative.
13. Screw the optional anchor spikes (Fig. A, Detail 1) onto the legs.
2a. Mark the bottoms of the legs. Bundle the legs together and mark the front and back faces as one pair and the two side faces as the other.
2b. Mark the first pair of faces. The dadoes on the front and back faces match, so they can be marked at the same time. Arrange the legs with the triangles at the top. After aligning the ends, draw reference lines every 8″ to mark the dadoes. Then go back and mark the slope, which runs outward from the
center of each pair.
2c. Mark the second pair of faces. Rearrange the legs with the circles at the top, and align the ends. Then mark the dadoes, using the same 8″ spacing. This time, however, start 4″ from the bottom. As you can see from the mark on the right, these dadoes are offset from the other pair of faces.
2d. Your bundle should look like this. Check to see that each leg has its two outside faces marked, that the marks are staggered, and that the slope of the dadoes is clearly indicated.
4a. Cut angled dadoes in the legs. Slide the leg in, topend first, making sure that its slope indicators run the same direction as the jig. Align the dado reference line on the leg with the top inside shoulder of the jig’s dado, clamp and rout. Remember: The reference line always marks the top of the dado and the slope indicator should always be in the router’s path.
7a. Assemble one face at a time. Frame each face by fastening the top and bottom slats to a pair of legs. Then mark, cut and install the middle slats.
• 35 lin. ft. (five 7′ lengths) of 1-1/2″ x 1-1/2″ stock
• 8 bd. ft. of 4/4 stock
• 68 #10 x 1-1/4″ RH brass screws (for the slats)
• 4 #8 x 1-3/4″ FH stainless steel screws (for the spire)
• 16 #10 x 1″ FH stainless steel screws (for the optional aluminum spikes)
• Weatherproof glue
• 8 lin. ft. of 1″ aluminum L-angle (optional).
Fig. A: Exploded View
Fig. B: Jigs for Routing Angled Dadoes
Fig. C: Tapered Pyramidal Spire
This story originally appeared in American Woodworker June 2002, issue #94