Page 155 - Construction Waterproofing Handbook

3.44 CHAPTER THREE
DECK-COATING APPLICATION

When deck coatings are being applied at a job site, it is the only time when golf shoes are
mandatory attire! Liquid deck coatings are required to be squeegee-applied to ensure suf-
ficient and uniform millage. The millage rate is too thick for spray applications, which can-
not also provide the uniform thickness required.
During application the squeegee is pushed, not pulled, to prevent the blade end of the
squeegee from being pulled down too hard against the substrate and applying too thin a
wet millage of material. Pushing of the squeegee blade maintains the blade in an upright
position and a uniform millage application.
This pushing of the squeegee requires that the mechanic walk through the applied mater-
ial, thus requiring the golf shoes so as not to damage the installation and have shoes stick to
the wet membrane. The material self-levels after installation, so that any minute impressions
the golf-shoe spikes leave are quickly covered by the material.
Most deck coatings also require that the material be immediately back-rolled after ini-
tial squeegee application to further ensure uniformity of millage. These applicators must
also wear the golf shoes, as do those applying the aggregate that forms the wearing sur-
face in the top coat applications. Figure 3.21 pictures the application process of a typical
deck coating application.
Substrate adhesion and proper substrate finishing are critical for successful deck-coating
applications. In general substrates must be clean, dry, and free of contaminants. Concrete
substrates exhibiting oil or grease contamination should be cleaned with a biodegradable
degreaser such as trisodium phosphate. Contaminants such as parking-stall stripe paint
should be removed by mechanical grinder or sandblasting (Figs. 3.22 and 3.23).

FIGURE 3.21 Deck-coating application. Note the pushing of squeegees in the background, back-rolling
of coating and spreading of the aggregate by hand in the foreground. All crew members are wearing golf
shoes. (Courtesy of Coastal Construction Products)