Page 494 - Construction Waterproofing Handbook

13.10 CHAPTER THIRTEEN
Therefore, the best advice is for any water test to keep it as simple as possible.
Duplicating rainfall only takes a water hose and sufficient water pressure. Anything else is
usually not necessary, and likely used to impress the client rather than being useful in
determining the reasons for water infiltration.
It is also important to remember that water tests can be overdone. Massive amounts of
water applied on certain portions of any envelope, such as masonry facades using damp-
proofing and flashing as a divertor system, can cause water infiltration even if the envelope
is functioning properly. If the amount of water applied to the envelope exceeds anything
considered as a normal weather cycle, the results are meaningless.
Using the information gathered from the leak documentation, construction documents,
and inspection, testing parameters should be outlined, in particular the specific area to be
tested. On above-grade portions of the envelope, most testing is done with a simple water
hose and spray nozzle that simulates general rainfall. Conducting a water test requires a
minimum of two people, one applying the water on the exterior and another inside to deter-
mine when water begins infiltrating. Radios should be available to enable the parties
involved to talk to each other during the test, advising when water begins entering and
when it is time to move testing to another location.

Vertical envelope testing
Testing should always begin at the lowest possible point of the area in question, and move
upward only after determining that the lower areas are not contributing to the leakage. The
test also should be limited to a controlled area of the surface and not allowed to overspray
adjacent components. Figure 13.3 shows the progression of steps in a water test on a typ-
ical masonry wall with a punch window.
Testing the lower elevations first before moving up to the window reveals if the
masonry wall is contributing to infiltration. Test the window sill area first and then the jambs
and then the window head flashing and sealant. Each area of the test should be com-
pleted using a specific amount of time, providing time for the water to travel into the
structure. This typically takes a minimum of 10–20 minutes, unless infiltration becomes
obvious sooner. If water infiltration does not appear, the testing should move to the next
higher elevation.
Referring again to Fig. 13.1, note the importance of starting water tests at the lowest
elevations. As an example, suppose that the membrane flashing was the cause of leakage
occurring in the building, permitting water that penetrates the EIFS system above from
entering into the building rather than being diverted to the drainage systems provided for
this water to exit beneath the pipe. It might first appear that water is entering directly at the
pipe penetration when in fact it is not. If water testing began above the pipe penetration, it
might appear to confirm such an assumption.
If the test is properly conducted by applying water at lower elevations, then moving
directly over the pipe, water should not infiltrate the envelope. However, once the water test
is raised to an elevation above the pipe, water entering through the EIFS systems is properly
diverted to the drainage mat down to the pipe where the membrane flashing that has failed
permits the water to enter into the envelope. In this case, a review of the documents in con-
junction with the test results should provide evidence that the leakage is probably occurring
due to the failed pipe flashing.