A foundation system using vertical piers and horizontal beams to support a structure above ground level, creating an accessible crawl space.

A pier and beam foundation is a foundation system that uses vertical piers or posts combined with horizontal beams to support a structure above ground level, creating an accessible crawl space beneath the building. This traditional foundation method elevates the structure on a framework of concrete, masonry, or steel piers that support wooden or steel beams, which in turn carry the floor joists and flooring system. Pier and beam foundations are particularly common in areas with expansive clay soils, flood-prone regions, or where access to utilities beneath the structure is important, as they provide better ventilation, easier maintenance access, and reduced ground moisture problems compared to slab-on-grade foundations.

Pier and beam foundations are used in various applications including residential construction in regions with challenging soil conditions such as expansive clay that can cause foundation movement, areas prone to flooding where elevation above ground level provides protection, historic preservation projects where the foundation system matches original construction methods, and retrofit applications where existing structures need foundation repair or replacement. This foundation type is also preferred in climates where ground moisture and humidity control are important, and in situations where future access to plumbing, electrical, or HVAC systems beneath the structure is anticipated.

The components and construction of pier and beam foundations include concrete or masonry piers that extend below the frost line and bear on stable soil or bedrock, typically spaced 6 to 8 feet apart depending on load requirements, horizontal beams (girders) made from wood, steel, or engineered lumber that span between piers and distribute structural loads, floor joists that span between beams and support the subfloor and finish flooring, and proper ventilation systems including foundation vents and moisture barriers to control humidity and prevent moisture problems in the crawl space. The system may also include cross-bracing between piers for lateral stability.

Fun Fact: Pier and beam foundations have been used for thousands of years, with ancient civilizations using stone piers and wooden beams to elevate structures above flood waters and provide protection from ground moisture and pests.

• Beam
• Beam Clamp
• Beam Pocket