What size of beam is needed to span 10 feet if used only for roof support?

The size of the beam needed to span 10 feet for roof support depends on various factors, including the type of material (wood, steel, etc.), the load it will carry, and local building codes. For a typical wooden beam, a common choice might be a 2x10 or 2x12, but calculations based on specific load requirements and spacing are essential. It's advisable to consult a structural engineer or local building codes to determine the exact specifications for safety and compliance.