What is a foundation beam?

A foundation beam is a horizontal, usually reinforced-concrete beam that absorbs the load of the walls and structure above it and transfers it to the piles or pile caps below. The beam often connects the pile heads into a single rigid whole.

Function and structure

The foundation beam forms the link between the superstructure and the pile foundation. The masonry or concrete walls rest on this beam, which in turn is supported at regular intervals by piles. Between the piles, the beam spans the distance freely, much like a girder.

Because concrete resists compression well but tension poorly, the foundation beam is fitted with reinforcement: steel bars that absorb the tensile forces. This reinforced-concrete assembly can carry large loads without cracking.

With a shallow foundation, the principle works slightly differently. There the foundation beam, also called a foundation strip, distributes the load over a wider area of the load-bearing ground, without the need for piles.

Application

Foundation beams are used in almost all modern residential and commercial construction. They ensure that point loads from piles or walls are distributed evenly and that the foundation behaves as one rigid whole. This prevents uneven settlement and keeps the structure stable.

Related terms

• Driven pile
• Pile cap
• Strip foundation
• Reinforced concrete

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