What size timber beam would be needed to span 6 meters?

The size of a timber beam needed to span 6 meters depends on various factors, including the load it will carry, the type of wood, and the design specifications. Generally, for a typical residential application, a beam of at least 190mm x 45mm (or similar) may be used, but larger dimensions like 240mm x 45mm could be necessary for heavier loads. It's essential to consult local building codes and possibly a structural engineer for precise calculations tailored to your specific situation.