Risk Management > Causes of Deterioration
Diagnosis and Prognosis
The underlying cause(s) of every conservation issue, problem,
deficiency and building pathology must be identified, monitored,
assessed, and eliminated and/or corrected before the resulting
condition caused by the problem(s) are treated.
Examining a house involves some of the same techniques that
doctors use on a sick person. A doctor reviews medical records
and asks a patient to describe any troubling symptoms. Analysis
includes visually inspecting the patient, a physical examination,
and, possibly, testing to identify signs of disease.
A diagnosis is developed based on these symptoms and signs,
the results of reliable tests, and the doctor's expertise and
experience with similar conditions. Possibly, the diagnosis
will identify the underlying causes: the disease itself. Then,
a prognosis will predict the expected course and complications
of the disease if left alone; or the outcome, if treatment occurs.
A treatment will be suggested to the patient for consideration.
If undertaken, the treatment will hopefully relieve the symptoms
while curing the disease. Preventive measures will be prescribed
to keep the disease from recurring.
Cause and Effect
A patient may have the flu. The symptoms may include a high
temperature, a cold, aches and pains. The cause is likely a
bacterial or viral infection. A doctor can prescribe medicine
to relieve the uncomfortable symptoms, but this will not get
rid of the flue. It is only once the underlying cause is cured
by either medication or by the patient's immune system
that the disease will go away. A vaccination or medication
may prevent an illness from recurring.
This example shows the importance of careful diagnosis and
treatment. It also explains that the cause must be treated to
cure the patient:; simply reviewing the symptoms will not work.
This analogy can be used for buildings just as well, with one
important difference: a body can heal itself. Buildings cannot.
They need the help of owners, craftspeople, and other professionals
to remove the causes of deterioration through careful preservation
It is unlikely that all the problems and causes will be discovered
during an initial building inspection. This may require detailed
assessment, followed by more analysis, testing and monitoring
-- over time, and under various weather conditions.
It is very important to understand the difference between
recording the symptoms of a problem and figuring out its underlying
cause. There are usually several causes, each serving to complicate
a particular problem. A correct preservation plan can be developed
only once each cause is discovered, analyzed and understood.
- defective products
- variations in products, quality control
Design and Construction Defects
- errors in design, style
- undersizing, poor connections
- poor construction methods
- faulty workmanship
- incompatible components
- location of structure (micro environment)
- geo-topographical location (site; macro environment)
- site orientation of structure
- subsurface conditions
- moisture (ground water, rain, snow, floods, storms)
- temperature (expansion / contraction, freeze / thaw)
- motion (gravity: settlement, ground subsistence, earthquakes)
- abrasion (wind, mechanical wear)
Chemical and Electro-Chemical Factors
- ionic solution, galvanic corrosion
- alteration and replacement
- lichens and plants
- rot and xylophagous insects
- neglect, lack of maintenance
- theft, vandalism, arson
- accidents (fires, leaks, floods, explosions)
- pollution, acid rain
- change in site/design
- destructive alterations
- inappropriate treatments
- poor "preservation" practices