How to Erect an Easy Arbor
A small arbor set over a front sidewalk or walkway provides a charmingly old-fashioned gateway to a house.
Lay Out, Dig Holes, and Set Holes
Use a framing square and some string with stakes to establish the outside corners of the arbor. Make sure it will be not only parallel to the sidewalk but square, as well.
Dig the holes with a clamshell or twist-type posthole digger. Mark the digger with a piece of tape or notch to indicate the correct depth. Dig each hole a couple of inches deeper than needed, then shovel in a bit of gravel so water will drain away from the post bottoms.
Set the posts in the ground and brace them so they will stay plumb as you work. Cut them to height later. Use pieces of 1×3 or 1×2 as temporary angle braces and stakes. Work with a helper, one person attaching the braces while the other checks that the post remains plumb. Position the braces so they will not get in the way as you attach the lattice pieces.
You could pour the concrete or tamp soil or gravel in the holes at this point. However, you would need to wait a couple of days for the concrete to cure before proceeding, or the posts might become loose as you work. It is best to anchor the posts after the structure is built.
Build the Arbor
Using a stepladder and a level set on a straight board, mark the tops of the posts for cutting to the same height. Use a square to draw a line around each post and cut with a circular saw.
Cut the 2×12 or 2×10 rafters to length so they overhang the posts 2 inches on either side. Use a string and a pencil to mark for a smooth curve at the top of one and cut the curve with a saber saw. Use the first piece as a template for marking the second. Have a helper hold each rafter in place while you drill and fasten them to the posts with 5 ½-inch carriage bolts.
Cut all the side pieces of lattice to the same length, so they overhang the posts one inch or so on either side. To attach the lattice, begin with a piece that is 2-3 inches above the ground. Hold it in place, check it for level, and attach it to the posts with 6d galvanized nails or 1 5/8-inch decking screws.
To maintain consistent spacing, use a spacer piece of 1×2 or 1×3. Set the spacer on top of the installed lattice piece and the next lattice piece on top of the spacer, and drive screws or nails. Continue working this way until you get to the top.
Cut the overhead lattice pieces so they overhang the rafters by one inch. Install the first piece near the edge of the rafters and use the spacer to install the others.
Anchor the posts by pouring concrete, adding tamped soil, or tamping in gravel. Finish the arbor by priming and painting it with two coats of high-quality exterior paint. It will be difficult to repaint after the plants grow. Or apply a water-repellent finish.
