What Is Pier & Beam Framing?

Post and Beam Basics

• When we say post and beam or pier and beam, we are referring to columns and beams. Columns are vertical, linear structural elements that work in compression, carrying loads applied to their top axially to the ground. An example of columns are those vertical members of the Lincoln Memorial. Beams on the other hand, are oriented horizontally (called the joist orientation) and work with their top half in compression and bottom half in tension. Ultimately though, the member works overall in compression. An example of a beam would be the two horizontal poles that hold up monkey bars at a playground because they are spanning horizontally to carry an applied load.

Construction Methods

• Post-and-beam or pier-and-beam construction is based on creating a structure out of many columns and beams to form a structural grid. Columns are erected and often set into a concrete foundation for base support. Then the columns are connected by the addition of beams from column to column at the tops of the columns. By doing this, the designer is creating a grid of verticals and horizontals, much like a mathematical grid. This grid can be extruded upwards to create a very tall structure, or out horizontally to create a flatter structure.

Materials

• Post-and-beam construction uses mainly lightweight wood and steel. These materials are easy to manage and mass produced. Lightweight wood is used on residential projects, and heavier steel is used on larger projects like skyscrapers. Wood is easy to move by hand (often a single worker can carry an entire column or beam made of wood) and easy to manipulate by shaping it with tools. Steel is easy to form and is very sturdy when creating large-scale projects.

Examples and Understanding

• Examining examples of pier-and-beam construction is the best way to truly understand how they work. One of the earliest examples of post-and-beam construction is Stonehenge. It is a prime example of columnar members holding the load of horizontal beam members. Granted, the columns are all made of stone, but the forces applied to the structure are clearly seen. Another great, yet more modern, example can be seen by going to the site of a residential home being constructed. It is highly advisable to go to a site and look at how these beams and columns are joined, and the kind of grid they form. This would be the best type of example of the structural system because you can see exactly how modern construction techniques are used and applied to post-and-beam construction.