Page 498 - Construction Waterproofing Handbook

13.14 CHAPTER THIRTEEN
Figure 13.1 presents a situation where destructive testing might be necessary. Assume
again that the pipe membrane flashing has failed, permitting water entering the EIFS
drainage system to enter the envelope at this point. If the construction documents were not
available it would be difficult, if not impossible, to determine the exact cause of leakage
without removing the dryer vent cover, sealant, and possibly even a portion of the EIFS
system at this area to inspect the membrane flashing.
Additional information on destructive testing is presented in Chap. 8. Obviously, it is
recommended that you limit the amount of destructive testing completed on any envelope
due to the difficulty in repairing the test area for watertightness and aesthetics. Testing
equipment is available that can be used to assist in leak investigation and possibly prevent
the need for destructive testing.

TESTING EQUIPMENT

There is a variety of testing equipment available for detecting leakage. Most of this equipment
will verify the presence of leaks, but few can pinpoint specific areas of envelope failure. The
equipment is often used in maintenance reporting, tracing any water infiltration into the enve-
lope before it causes damage to interior areas.
Equipment includes moisture meters that can register the percent of moisture content in
any substrate that can be probed. Moisture meters generally have two sets of metal, needle-
like attachments that are inserted into a substrate to detect moisture. These meters are
applicable to substrates such as wood, stucco, EIFS, paints, and other similar types of
cladding. They do not work with stone, curtain wall, masonry, precast substrates.
While providing evidence of entrapped moisture and the relative amount of moisture,
these meters cannot pinpoint the exact cause of leakage, only the areas affected by mois-
ture. The meters can be useful to document the extent of leakage and limit the inspection
for the problem to a small area by outlining where in the substrate moisture is present.
There are also a variety of thermographic infrared testers available. These tools can
reveal the presence of entrapped moisture in envelopes and they are widely used in roof
inspections. The equipment measures the amount of heat emitted from objects. The equip-
ment is often used at night, when entrapped water retains heat accumulated during the day-
light hours and releases it more slowly than surrounding areas. A warm zone on the
measurements reflects the presence of water.
The equipment is used extensively on roofs, especially when single-ply or multi-ply
asphalt materials have been used that permit water to travel beneath the roofing material
and substrate. The infrared equipment can be used to locate the extent of water entrapped,
and narrow the search for the actual breach in the membrane to a smaller area. The equip-
ment can be used on all portions of the envelope, including vertical surfaces and plaza
decks or balconies. While the equipment cannot pinpoint the cause of leakage, it can be
useful to narrow the focus of the search to a limited area.
Nuclear testing equipment is also available, typically for use on roofs or plaza decks or
other horizontal areas that might contain trapped moisture. Nuclear equipment works not by
taking an x-ray of the substrate, but by sending a signal into the deck which is capable of
measuring the hydrogen atoms that water contains. Since it is capable of measuring the