Page 151 - Construction Waterproofing Handbook

3.40 CHAPTER THREE
cracks or to adjust to thermal movement. Additionally, it is difficult to repair the water-
proofing membrane layers once the asphalt is installed. There is no way to remove overlays
without destroying the base coat membrane. Asphaltic systems are not recoatable. For
maintenance, they must be completely removed and reinstalled. (See Table 3.17.)

TABLE 3.17 Asphalt Deck-Coating Properties
Advantages Disadvantages
Protection of membrane by asphalt overlay Weight added to structure
Longer wearing capability Movement capability restricted
Thickness of applied system Inaccessibility for repairs

Latex, neoprene, hypalon
Deck coatings are available in synthetic rubber formulations, including latex, neoprene, neo-
prene cement, and hypalon. These formulations include proprietary extenders, pigments, and
stabilizers. Neoprene derivatives are soft, low-tensile materials and require the addition of a
fabric or fiberglass reinforcing mesh. For traffic-wear resistance, this reinforcing mesh
enhances in-place performance properties such as elongation and crack-bridging capabilities.
Reinforcing requires that the products be trowel applied rather than roller or squeegee applied.
Trowel application and a finish product thickness of approximately 4 in increase the
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in-place costs of these membranes. They also require experienced mechanics to install the
rubber derivative systems. Trowel applications, various derivatives, and proprietary for-
mulations provide designers with a wide range of textures, finishes, and colors.
Rubber compound coatings have better chemical resistance than most other deck-coat-
ing systems. They are manufactured for installation in harsh environmental conditions
such as manufacturing plants, hospitals, and mechanical rooms. They are appropriate in
both exterior and interior applications.
Design allowances must be provided for finished application thickness. Deck protru-
sions, joints, wall-to-floor details, and equipment supports must be flashed and reinforced
for membrane continuity and watertightness. Certain derivatives of synthetic rubbers
become brittle under aging and ultraviolet weathering, which hinders waterproofing capa-
bilities after installation. Manufacturer’s literature and applicable test results should be
reviewed for appropriate coating selection. (See Table 3.18.)

Urethanes
Urethane deck coatings are frequently used for exterior deck waterproofing. These are avail-
able for both pedestrian and vehicular areas in a variety of colors and finishes. Urethane sys-
tems include aromatic, aliphatic, and epoxy-modified derivatives and formulations.

TABLE 3.18 Latex, Neoprene, and Hypalon Deck-Costing Properties

Advantages Disadvantages
Excellent chemical resistance Trowel application required
Good aging and weathering Fabric reinforcement required
Good wear resistance High cost