Do it Yourself Arbors

Construction

• Building a wooden arbor calls upon the general rules of carpentry for the placement of components. A stand-alone arbor is basically constructed in the same way as an arched walkway. The size of the arbor should be determined by any existing building structure, like a patio or gate, and by any walkways.

  Four posts, each 4 inches by 4 inches, are tied to an arched top with lintels and covered with lattice. The posts should be set in the ground like fence posts, depending upon the ground surface material. This creates a secure structure. Posts are cut for desired height, generally from 7 to 9 feet, taking into account the height added by the arched top. Two-by-6-inch members, cut to equal dimensions, connect two of the posts at the top, middle and bottom. The other two are connected identically. The two sides of the arbor are now ready.

  Create the two arched sides for the top in the desired radius. The arches will have to be cut from several pieces of wood and attached prior to cutting. The first arch should be used as a template for the second. Each arch is attached to one set of connected posts and secured across the span with rafter. Attachments can be made by using post-and-beam-type connections or purchasing mechanical fasteners from your local building supplier. The final step in completing the arbor is covering the sides and top with lattice.

  In most cases, the posts should not be placed farther than 8 feet apart. Rafter size is determined by the width of post placement. Posts that span 8-12 feet can use 2-by-6 rafters. Posts that span 12-16 feet should use 2-by-8 rafters and so on. The distances between the rafters should never be more than 16 inches but can be less. Connections can be made with screws, through-bolts or decorative mechanical fasteners. Sometimes the use of all connection types is required.

Considerations

• Pergolas, trellises and canopies are similar to arbors in construction and offer alternatives that may better suit available space. A pergola is simply an overhead canopy that is not covered with roofing material, a trellis or fabric. The knowledge of general carpentry practices is a prerequisite to building an arbor, or any of the alternatives, as a safe structure must be the final result. Some arbors and other overhead structures require city permits and building code inspections.

Special Vocabularly

• Arbors have a number of special terms to describe their components. The abacus is the top part of the capital of the column. Dentil work is a series of decorative blocks that projects from a molding. A set of beams resting over the columns is called the entablature. The end of the rafter, which can be simple, contoured or custom detailed, is called the rafter tail. Purlins are the parallel pieces that comprise the overhead trellis structure. A boot is the bottom of the post that decorates the foot plate and adds visual weight to the structure.