i'm doing preliminary planning for a garage structure- would like to verify dimensions of a header above the garage door opening span of 18'.
recommendation from supplier is 2 lvl beams 1-3/4 x 11-3/4. Roof will be a truss system-hipped, decked and shingled.

Will these two beams be plenty? (I will have clearance for their next size- 1-3/4 x 13-3/4.
just wondering. thanks

Not enough information to know an answer...we don't know the loads it has to carry at all, and we don't know te snow load required in your region...is there a storage level above the garage or not? Or does it carry only roof load? Even if we knew those things, I don't believe it is proper to try to design structural elements sight-unseen. Too easy for there to be some important information which we don't know.

I always get this information from the truss supplier, call them and they will figure it out for you.