Page 490 - Construction Waterproofing Handbook

13.6 CHAPTER THIRTEEN
Testing can then be commenced to determine if the divertor system is contributing to water
infiltration to interior areas.
The documents can also be useful when leakage is occurring at above-grade portions of the
envelope that are not readily accessible for inspections. For instance, in multistory buildings,
the envelope might not be accessible without scaffolding or swing-stage scaffolds. Documents
and visual inspection from interior areas looking out through windows or curtain wall com-
ponents might be the best initial means to conduct a leakage investigation. If this initial inspec-
tion is not sufficient for determining the cause, scaffolding or some means of accessing the
area such as a hydraulic lift or available window-washing equipment would be required to
complete the inspection. If this is the case, a water test might be scheduled at the same time
to confirm any opinions formed from the visual inspection.
Below-grade areas also are difficult to inspect visually, since the exterior portions of the
envelope are not accessible. Below-grade inspections are usually limited to visual reviews
of the landscaping and site drainage on the exterior. On the interior side of below-grade
area, finishes applied to the structure such as drywall also hamper visual inspections. More
often than not, some destructive removal of finishes or landscaping is required to view and
inspect below-grade leakage problems. Note, however, that destructive removal of sur-
rounding areas can further damage the envelope, particularly on below-grade waterproof-
ing systems that can be easily damaged during backfill removal.
The purpose of any visual inspection is to confirm the construction methods described
in the building documents, document any obvious failures in the envelope components,
reveal any poor or improper maintenance, and either provide recommendations for repairs
that should prevent further leakage or outline the steps necessary for further testing of the
envelope to determine the exact cause of leakage. Figure 13.2 provides a detailed guide for
use in visual inspections of common building envelopes. It is useful to ensure that all pos-
sible contributing factors to the leakage are inspected. The inspection guide can be used to
highlight areas that require maintenance or repairs before they also contribute to future
weatherproofing problems.
Obvious problems such as deteriorated sealants, insufficient drainage, and cracks or
holes in the substrate can be repaired immediately, and the area monitored to confirm that
the problem has be resolved. If however, these corrective measures do not resolve the prob-
lem and no other obvious possible causes are evident, then testing is required to determine
the reasons of water infiltration.

Testing
Testing for water leaks is not a science. Water tests do not require an engineering degree
to be performed properly. Only if the situation might result or be involved in legal action
would it be necessary for the testing to be monitored by an engineer or consultant who has
the credentials to testify in court as to the cause(s) of leakage. Even in this situation, it is
often not necessary to spend vast sums of money on elaborate equipment or destructive
tests to document the leakage.
Mother Nature does not use calibrated funnels, measured amounts of water, and other elab-
orate equipment to create the leakage; therefore the same should not be required of the water
test equipment. If a leak occurs, the exact amount of water infiltrating during a specific time
frame is not useful information to anyone. A water test is necessary only to document and
determine where and how the water is bypassing the envelope barrier and divertor systems.