It is the purpose of this Digest to describe some of the problems that this type of construction has produced and to show that, unless the underlying faulty concept of wall design is corrected, it is not reasonable to expect that present practice will be able to prevent them. Some Problems Of all problems, the presence of water inside a building is reported most frequently. Water dripping from ceilings or running down walls is not tolerated for long without protest, and in some cases it will cause a disruption of activities. Water on the inside surface of a wall does not cause so great a disruption but in both cases there can be a severe deterioration of the appearance of walls, ceilings, and floor coverings, or the contents of the room. Condensation on windows and window frames is a similar problem but, because the immediate cause is more obvious, it does not provoke the same protest as does water that emerges mysteriously from wall panels or through ceilings.
Some designs accept it as inevitable, and drainage gutters are provided.
Unfortunately, however, these do not always work satisfactorily as the drain hole often becomes plugged with frost or dirt, or an inward air pressure prevents the water from draining away. A less obvious, but more serious, form of deterioration is the corrosion of the metal connections that hold the precast panels onto the structure of a building. Should one panel break loose, all other panels would be suspect and the remedial work required would be very costly. Only one connection failure has been reported to the Division, but other connections have been seen to be wet or very rusty after comparatively short periods of service. It should be pointed out that a failure can result not only from the removal of metal by corrosion, but also from expansive forces set up by the products of corrosion, which have a much greater volume than the parent metal.