Saw blades should be stored separately. Keep each blade secured between two pieces of plywood, fastened together by a nut and screw that goes right through the center of the blade. Blades that are chipped, bent or in any way damaged are discarded at once.
When hiring a contractor, insist on a complete written contract. Know exactly what work will be done, the quality of materials that will be used, warranties, timetables, the names of any subcontractors, the total price of the job and the schedule of payments.