We have 20 feet of windows on our terrace overlooking the ocean and a narrow deck 6 feet wide. Should we use 5 sliding doors that kaleidoscope back into one pack of windows 4 feet in length or should we use 7 bifold doors that collapse into 14 inches and hinge 36 inches out from the hinge. The bifold doors insure great openness onto the terrace, but I've been told that the bifold doors present problems in maintenance and we are on the Pacific Ocean with attendant problems of a marine climate. What to do?