Page 489 - Construction Waterproofing Handbook

LEAK INVESTIGATION AND DETECTION 13.5
5. Make note of all unusual construction techniques. Often, designs require installations
that local craftspeople cannot duplicate properly during construction. These areas might
include highly decorative envelope finishes such as copper standing seam copings that
should be carefully inspected in the field for contributing to the existing leakage.
6. As appropriate, review the structural, mechanical, and landscape drawings. These doc-
uments might provide some insight into the causes of leakage, such as mechanical pro-
trusions in a planter that have inadvertently damaged the waterproofing membrane.
7. If available, review shop-drawing submittals. These provide insight into the systems
and products used in the original construction, including any warranties and product
capabilities. The shop drawings also might be useful in determining if incompatible
systems were installed, such as butyl sealants in contact with urethane membranes.
Once all available construction documents have been carefully reviewed and specific
notes taken relating areas requiring further study, a field inspection can begin. The docu-
ment notes should be taken on the field inspection, as well as any drawings or details that
need to be compared to actual in-place conditions.

Inspection
After the records pertaining to reported leakage have been reviewed, a visual inspection is
in order to determine what are the possible causes and where they might be located. A
visual inspection can provide immediate evidence of possible leakage causes, but in many
cases testing is required to either verify the cause or actually determine where the enve-
lope has been breached.
Visual inspections will often provide evidence of the contributing factors of water infil-
tration, including failed sealant joints, faulty or cracked mortar joints, improperly func-
tioning transition or termination detailing, and clogged drainage systems. When a visual
inspection reveals these evident failures, corrective measures might be planned immedi-
ately and the area previously prone to leaks monitored to determine if the corrective mea-
sures have resolved the problem.
In many situations however, the visual inspection will not provide immediate evidence
of obvious failure or breaches in the envelope. This is especially true with divertor systems,
such as flashing systems, which allow water to enter the envelope but then divert the enter-
ing water back out to the exterior. In this type of construction, visual inspections are not
able to investigate the actual components of the divertor systems since they are hidden
behind the building envelope facade components.
Should leakage be occurring in such areas, either a water test has to be conducted to
confirm that the leakage is occurring within the envelope components, or a destructive
visual test must be made. The later is completed by removing portions of the envelope
facade to expose the backup or divertor systems. This can be a costly method, and in most
cases it is best to first complete a water test in the area to confirm that leakage is attribut-
able to the systems in question before a destructive inspection is commenced.
In similar situations, access to the original construction documents can also provide
insight into the causes without having to complete destructive testing. The documents,
especially as-built drawings, should provide sufficient details as to the methods used to
construct the divertor system without having to remove façcconstruction methods used.