1.75" gap at the bottom of a French door
I recently put in tiles and got a 5' wide french door hung. The door is going from a hallway to an drop down enclosed patio addition. I was out for the holidays, and the work was done by a friend of a friend, when I got back, the bottom of the doors were 1 3/4 inch off the newly installed tile. The tiles goes all the way to the edge with a bullnose and covers the drop down as well. The job was not expensive ($560), and I told him I wanted to use a wooden threshold instead of the built in aluminum for the door. I asked him if we could redo the door lowering, but was told it was be a lot more work, and difficult to get right as the door was a pain to put in in the first place. He recommended that I just use a 1 1/2" tall threshold, perhaps stacking one on top of another. Is that way too tall for a normal threshold and what else can I do to handle this gap? There can't be too much gap as the enclosed patio is not insulated very well, and I'll need to bolt the bottom of free side down as well.