Page 200 - Construction Waterproofing Handbook

ABOVE-GRADE WATERPROOFING 3.89
TABLE 3.30 Protected and Inverted Roofing Properties

Advantages Disadvantages
Protection from vehicular and Difficult to repair
pedestrian damage
Protected from weathering Drainage problems occur frequently
Provide multiple use of roof areas Subject to insulation deterioration

Deck coatings for roofing
Among the simplest and most successful but most underused roofing systems are deck-
coating systems. These materials are used primarily for waterproofing pedestrian and
vehicular decks as previously discussed in this chapter. Deck coatings applied as roofing
systems provide seamless applications, including terminations and transitions, and are
completely self-flashing. They can be applied over wood, metal, and concrete substrates.
The only major disadvantage in roofing application of deck coating is that insulation
must be installed to the underside of the exposed envelope portion. If this is possible, deck
coatings provide numerous benefits when installed as roofing systems.
Since deck coatings adhere completely to a substrate, water cannot transverse longitudi-
nally beneath the system. Therefore, should leakage occur, it will be directly where a mem-
brane has failed and easily determinable. These membranes are resistant to pedestrian and
vehicular traffic, providing resistance to abuse that most other roofing systems cannot.
Repairs are easily completed by properly repairing and recoating an affected area. Any
equipment changes, roof penetrations, and so forth, can be made after the initial roof
installation. These repaired areas also become seamless with the original application.
Deck coatings are applied directly from manufacturer’s containers in a liquid. This appli-
cation eliminates the need to heat materials, seam, and use spray application, which are
required with other roofing systems. By providing the simplest installation procedure, deck
coatings eliminate most human error and result in successful roofing systems for building
envelopes. (See Table 3.31.)

ROOFING INSTALLATION

Mechanical equipment, plumbing stacks, and electrical penetrations are often poorly
detailed, presenting almost impossible conditions in which to install roofing materials. The

TABLE 3.31 Deck Coatings Used for Roofing Properties
Advantages Disadvantages
Seamless applications Insulation must be placed on the underside
of the deck
Seamless termination and Control of millage thickness
transition detailing
Allows roof areas to be used Subject to blistering by negative
for different purposes moisture drive