Page 473 - Construction Waterproofing Handbook

ENVELOPE TESTING 12.13

FIGURE 12.11 Static pressure water test. (Courtesy of
Architectural Testing, Inc.)

Dynamic pressure water testing
Dynamic pressure water testing applies water and wind conditions directly to an envelope face.
Airplane prop engines, (Fig. 12.12), are used to force water against the composite envelope from
spray nozzles equally spaced and mounted to frames, (Fig. 12.13). This test usually simulates
the most severe conditions, such as hurricane- and tornado-force winds and rain conditions.
Water applied in this manner is forced both vertically and laterally along the envelope
face to recreate conditions encountered in high-rise construction. This method of wind load-
ing, with the addition of water, can force water into envelopes not capable of withstanding
designed or expected wind loads.
Glass can bend or flex away from mullions or glazing joints, allowing sufficient space
for water to penetrate into interior areas. Structural conditions can also change during wind
loading to create gaps or voids or even failure of envelope components, (Fig. 12.14), allow-
ing direct water infiltration.
Amounts of water and wind introduced onto the envelope can be variably applied to
simulate maximum conditions expected at a particular job site. A combination of weather