Table of Contents
Introduction: An arbor or a pergola?
This structure might be called either an arbor or a small pergola, but we will call it an arbor. What’s the difference?
Definition of an arbor
A shelter of vines, branches or latticework covered with climbing shrubs or vines. A walk-through garden structure that can support plants and generally complements the landscape.
Definition of a pergola
A structure usually consisting of parallel colonnades supporting an open roof of girders and cross rafters. A structure with open wood-framed roofs, often latticed and supported by regularly spaced posts or columns, and covered by climbing plants such as vines or roses, shading a walk or passageway. Pergolas are distinguished from “arbors,” which are less extensive in extent and structure.
This arbor is also designed to be very sturdy, as in a lot of cases an arbor can be a rather flimsy garden structure. This arbor consists of 100×100 (4″x 4″) posts concreted into the ground, 200×100 (4″x 8″) beams checked and bolted to the posts and 100×50 (2″x 4″) rafters fixed to the beams.
About the wood sizes
The size of the wood referred to in his project is the actual size, which is the size of the wood after it has been dressed (smooth, planed, finished).
For example: When a pieces of wood 2″ x 4″ rough size (called the nominal size) is dressed (smooth, planed, finished), it becomes approximately
1 1/2″ x 3 1/2″ in size, which is the actual size.
All measurements throughout this project are given in both Standard/Imperial inches, and Metric (mm).
The measurements are given first in inches, followed by millimeters (mm) in brackets ( ).
1 1/2″ x 3 1/2″ means wood that is 1 1/2 (one and a half) inches thick by 3 1/2 (three and a half) inches wide.
And the equivalent in metric…
90mm x 45mm means wood that is 90 millimeters wide by 45 millimeters thick.