I am installing a slider on the back wall of a walkout basement. The door is standard 72"w x 80"h vinyl. My problem is this. The wall is an exterior wall and of course is load bearing. There was an existing roughly 90" picture window in place which i removed and framed back in. This had the standard double 2x10 sandwich header above it. Measurement from basement floor to first floor joists is 85". This only leaves me ~5" to play with for a header to span 6ft. There are 2 floors above the basment. Common sense, although not being an engineer, would tell me there is a -ton of weight on this wall. Would a 4-5" depth I beam work? Any other options with wood???
I would be careful about assuming a glulam would work. You state you have 5 inches of depth to work with. If this is accurate, then the largest glulam you could use would be five inches deep, unless you extend into the floor above. I assume there is a maximum width you could work with also, because of the block width, and not wanting to extend into the room, but perhaps this is not an issue.
In any case, a five inch deep glulam is not likely to provide anywhere near enough strength for your application, but of course you are going to check this with your structural engineer. I would ask them to consider a steel beam, more likely to work in this case.