A monorail system is, however, no solution for all facade maintenance jobs. There are buildings that are too tall for a monorail cradle to reach. This has to do with the amount of wire ropes and power cables needed to span the vertical length of the building. As the hoist units of a monorail system are in the cradle, the amount of cable will increase the weight. Thus limiting the maximum reach of a monorail system to approximately 100 meters (328 ft).
Another disadvantage of a monorail system is the fixed distance from the facade. When a building has protruding or retracting elements, or a zigzagging facade with shifts between floor levels below the point where the monorail track could be installed, than the cradle cannot reach this area. In these situations a roof car could be more suitable, as it can expand and retract and thus bring the gondola closer to the facade at any level.
Last but not least, careful consideration needs to be made on how workers are going to use a monorail system. They have to be able to get into the cradle safely, so a safe location has to be appointed. When a cradle is detached, when not in use, the workers will have to attach the system again before use. For this a facility, such as a hatch, needs to be placed in the facade or the ceiling. The attaching and detaching needs to happen in a proper manner as to put no one at risk. So workers will need training on safe equipment usage.