What size beam do you need to span 8 meters?

The size of the beam needed to span 8 meters depends on several factors, including the type of material (wood, steel, concrete), the load it will support (live load and dead load), and the beam's design (e.g., continuous, simply supported). For example, a steel I-beam may be smaller than a wooden beam for the same load. It's essential to consult structural engineering tables or a professional engineer for specific calculations and recommendations based on the project's requirements.