Lynn
My side walls are glued on and I have screws at the top an bottom. That will be covered with trim so they are flush. The top of the side is screwed into the spars and the bottom into the floor from the outside. The glued frame is then screwed to the floor also.
I did worry about it at first but the roof is the same way. Glued to all the spars and ends with screws at the ends where I will have trim.