A grade beam is a long, reinforced concrete beam that transfers the weight of a building to supporting structures as part of the building's foundation. It is called a grade beam because it is built at grade or ground level.
Grade beams are integral parts of most shallow building foundations. They are commonly used in conjunction with rubble trench foundations and work to protect the building's walls from moisture, in addition to spreading out the load of the building. The grade beams are poured on tamped gravel in trenches before the walls are constructed on top of them, and they spread the weight from the structure to the tamped gravel underneath.