Choosing the Right Posts and Supports for your Signs

California, Utah and Oregon are among the many states that use wooden posts for signs. The signs range from 4x4 inches for the smallest signs up to 6x8 inches, with box beam sizes, for the larger guide signs. The larger signs are often composed of laminated plywood.

In order for the sign post to break away if struck by a motor vehicle, the posts must be above the 4x6 inch size and drilled perpendicular to the flow of traffic. The signs must also be tough enough to withstand great forces of wind and other non-impact forces.

Temporary sign posts can be composed of non-treated wood, but permanent wooden sign posts must be made of stronger redwood or softwoods that have been pressure-treated.
Steel posts are also widely used for traffic signs. The four main types of steel shaped sign supports are: U-channel, square tube, tubular (or pipe shaped) and I-beam. These shapes are described below.

U-channel posts are normally used in light construction and maintenance applications. The posts are relatively inexpensive and simple to put together and force into the ground. If more than three U-channel posts are used on a single sign, a breakaway addition should be added. Weight per foot defines the size of a post, such as "3 pound/foot post".

U-channel posts do have a couple of disadvantages. For example, they do not have the ability for mounting signs at right angles on the same post and it has a lower loading capacity than other posts.

Square Tube posts are usually perforated with holes for mounting at one inch spaces, and are (as their name implies) square shaped. The outside square measurements actually define their sizes. Size ranges of standard square tubes measure 1-1/2 inches to 2-1/2 inches in 1/4 inch increments.

A "telescoping" post can be created by inserting another smaller square post inside the larger post. This procedure makes the square tube post stronger.

Posts and Supports for Signs

Choosing the Right Posts and Supports for your Signs