To predict the effectiveness of any action to correct defects it is necessary to take account of the intended use of the building and to obtain a comprehensive understanding of the causes of the defects and of the resultant damage.
Where faults exist, the wisdom of intervention will depend on various factors, such as the balance between the detrimental side-effects of remedial work and the consequences of delaying or avoiding repair. Germane considerations vary but, in habitable building, the following are common concerns:
· Do the defects jeopardise structural integrity or are they a manifestation of structural decay?
· Will they permit water ingress and, if so, will the water cause damage?
· Do they mar appearance or otherwise interfere with the perceived quality of the building and, if so, will the value of the building be lowered?
A thorough investigation should lead to a prognosis which addresses such questions as:
· Are there benign faults, which will not cause damage or impair performance?
· Are there malignant faults, which will destabilise, compromise or otherwise degrade the building?
· Is the visible damage a manifestation of ongoing progressive failure or decay?
· Is appearance compromised?
· Is there a loss of amenity, performance or value?
· Is the integrity of any part of the building impaired?
The visible manifestations of defects are often symptoms of underlying failure. Treating the symptom and not the cause often provides no more than short-term relief. Eliminating every defect will correct the building’s performance, but can be unnecessary. Tackling the mechanism of failure, so as to break the chain of events which is causing damage or annoyance, can provide an effective remedy without necessarily removing the originating defects. The available remedies for cracking and corrosion damage in reinforced concrete illustrate this point.