Span/load beam questions really cannot be answered. You will need to have the plans looked at by a engineer. At the very least the lumber yard selling the beam may have an on-staff engineer to have a look at it.
Roof Line 30 Foot Span
Use a steel beam.. That would be code.. steel w10x15 (50ksi) I beam.
It depends on the roof load and the actual clear span. Off hand, I would guess htat you haven't given this much thought. A rule of thumb for a steel truss is one inch per foot of span or in your case 40 inches. If you want to use a steel I-beam, you can get that from a good municipal library from the steel beam institute, but you are going to need a crane to place it. Dieter in Cincinnati
big one
That really depends upon the load you need to carry and the material that the beam is made of.
I'm afraid we do not have all the information needed to amswer your question. Your safety is important, and you would be better served to discuss your needs with a engineer that can look at the whole picture.
What size steel I beam do I need to span a 32 feet garage with a floored storage above and no posts
Whether an 8x4 beam can support a 16-foot floor span depends on the load it will carry and the type of material used. Typically, an 8x4 (which I assume refers to an 8-inch by 4-inch beam) may not adequately support a 16-foot span for standard residential loads without additional support, such as posts or a different beam size. It's crucial to consult local building codes and a structural engineer for precise calculations and recommendations based on the specific application.
the beam has a total volume of 60ft 3 what is the maximium horizontal gap that the beam can span
A 4x8 beam may not be adequate to span a 20-foot pergola without significant support. The ability to span that distance depends on several factors, including the type of wood, load requirements, and local building codes. Typically, larger beams or additional support posts would be needed to ensure structural integrity and safety. It's advisable to consult a structural engineer for specific recommendations.
The recommended patio roof beam span according to the patio roof beam span table is typically around 10-12 feet.
The recommended pergola beam span according to the pergola beam span chart is typically around 12-16 feet, depending on the specific design and materials used.