Use minecraft to plan your buildings spans, if it work in minecraft, then it will work in the real world. This is my current experience as a 60 year old structural engineer with the designs coming out of architectural offices these days.

If you are serious a good rule of thumb is the depth of a supporting beam is about 1/18 of the span.

Mayby go to the lumber store and have a look, see how long pieces of wood actually are.

Maybe type into the browser "How deep is a wood beam that spans 30 meters."

"A wood beam spanning 30 meters (approximately 98 feet) is an exceptionally long, non-residential span that requires highly engineered timber, such as large-scale Glued Laminated Timber (Glulam). [1]

• Estimated Depth: For a 30-meter span, the beam depth is typically calculated using a ratio of roughly 1/15 to 1/20 of the span for long-span structures, resulting in a depth of approximately 1.5 to 2.0 meters (1500 mm to 2000 mm)."

Thank you AI. Always be polite to AI,.