Specialty Roofing - Plaza Deck

PlazaDeck Systems

“Expand Your Living Space... And Help Increase The Resale Value Of Your Property!”

Choosing a GAF PlazaDeck (i.e., walkable) Waterproofing System for your roof or balcony can:

  • Add usable square footage to your property

  • Increase resale value

For a surprisingly modest investment, GAF PlazaDeck Waterproofing Systems can turn an ordinary roof or balcony into:

  • A sundeck or patio

  • A play or recreation area

  • Outdoor restaurant seating

  • An employee break area

  • Almost any kind of usable space: “It’s like adding a back yard... to your roof!”

Understanding PlazaDeck Systems...

Choosing and specifying a GAF PlazaDeck waterproofing system is easier than you think. Once you decide how you would like to use the space, just follow these four steps:

Step 1... Have a design professional verify your roof substrate

Step 2... Choose your waterproofing membrane

Step 3... Choose your protection layer

Step 4... Choose your surfacing layer

The choice of waterproofing membrane and surfacing layer are often made based on the final use for your PlazaDeck system. To determine the best options for your application, consult the chart titled “Putting All The Pieces Together”.

Step 1: Verify Your Roof Substrate...

PlazaDeck systems have special substrate requirements. The roof deck or underlying insulation must:
  • Be Stable...
    Without excessive deflection that would allow the walkable roof surface to move under normal usage

  • Provide Positive Slope To Drain...
    So that water does not collect either on the walkable roof surface or within the PlazaDeck assembly

  • Provide High Compressive Strength...
    So that the roofing membrane will be fully supported at points of concentrated weight and impact

  • Consist Of Structural Concrete...
    With minimum 2500 psi compressive strength

  • Some Systems...
    May require tapered isocyanurate insulation with a high density compression board, like Securock®* roof board or DensDeck Prime®**, min. 500 psi compressive strength

Waterproofing systems for smaller areas (up to 1000 sq. feet ) like balconies can omit insulation, however the surfacing options for this application are limited to tile embedded in mortar.

Before proceeding, a design professional must:
  • Verify the ability of your structure to accommodate a PlazaDeck system

  • Assure that the materials are compatible with each other and are installed in accordance with manufacturers’ specifications

  • Confirm that the design will perform as intended and meet your expectations.

Step 2: Choose Your Waterproofing Membrane...

PlazaDeck systems also have special waterproofing membrane requirements. The installation of a superior waterproofing membrane is the safest choice. The membrane must be:
  • Exceptionally strong and durable... and have excellent waterproofing characteristics. (Unlike at-grade or below-grade waterproofing applications, for which some minor leakage can often be tolerated, walkable roof applications are usually located over finished building areas where even a minor leak is to be avoided.)

  • Resistant to damage...for example, in the event that the surfacing materials need to be removed to allow changes or amendments to the roofing membrane, the membrane must be resistant to damage during that process.

Quick Tips
  • For Balconies…
    For 1000 sq feet. or under, liquid applied elastomeric membranes with or without fabric reinforcement may be the best option. GAF Topcoat® Surface Seal or CRT liquid membranes are especially suited to working in these confined spaces.

  • For Roofing Applications…
    Two or three ply RUBEROID® polyester-reinforced modified bitumen membrane systems, hot or cold applied for redundancy and resiliency, or a 60 or 80 mil fully-adhered TPO membrane with heat welded seams, especially suited for PlazaDecks that may incorporate garden areas like GAF GardenScapes™ systems.

Step 3: Choose Your protection layer...

The protection layer must physically protect the roof membrane from the surfacing materials installed over it, but must not interfere with positive drainage at the membrane level. It must:

  • have exceptional resistance to crushing failure

  • prevent direct transfer of concentrated point loads and impact loads to the roof membrane,

  • provide long-term physical and chemical compatibility with the roof membrane

Most GAF PlazaDeck assemblies utilize one of two roof membrane protection materials: Rubber Pads (used with concrete paver surfacing) or Reprocessed rubber pads, min. 3/16” thick (installed under concrete paver pedestals and wood support blocking with concentrated point-loading).

PVC/Polypropylene (used where surfacing load is evenly distributed) Heavy-duty drainage layer with knit geotextile filter fabric, min. 1/2" thick.

Step 4: Choose Your surfacing Layer...

Surfacing materials selected for walkable roof applications must resist normal usage conditions, including frequency of use, impact loads and concentrated loads, and the weathering effects of the sun, rain, ice, and snow.

The surfacing materials should require minimal maintenance and repair to avoid physically disturbing the roof membrane or contaminating the roof membrane with penetrating sealants and similar treatments. The surfacing materials must be within the allowable weight capacity of the structure, and provide the desired aesthetic appearance.

GAF PlazaDeck Roofing assemblies are available for use with all traditional walkable roof surfacing materials and systems, including:

  • Precast concrete pavers, with or without pedestals

  • Paving stones, brick or tile, set in sand or mortar bed

  • Wood decking panels

  • Wood decking with wood support blocking

  • Granulated rubber play surface pavers

  • Cast-in-place concrete

As an additional option, extruded polystyrene insulation board, min. 40 psi compressive strength, can be incorporated into many GAF PlazaDeck Roofing assemblies between the roof membrane and surfacing materials.

Putting All The Pieces Together...

Selecting PlazaDeck components based on your specific application

Maximize Your Roof Investment With These Unique Resources!

Diamond Pledge™ Guarantee -
The industry’s premier roof guarantee with true “edge-to-edge” coverage. Includes coverage for the entire Weather Stopper Integrated Low Slope Roofing System. And unlike conventional guarantees, some systems are even covered for ponding water, blistering, field-fabricated metal, and much more (see guarantee for details).

Well Roof® Guarantee Advantage -
The single best way to extend the life of your roof is to perform regular inspection and maintenance. GAF believes so strongly in this practice that it offers its unique Well Roof® Advantage program: a 25% extension of the length of your Diamond Pledge® Guarantee — FREE — when you invest in a regular maintenance and inspection plan!

Factory-Certified Contractors -
GAF selects only the top 4% of roofing contractors for membership in its factory-certified contractor program. GAF’s workmanship guarantees are available only through this exclusive group.

Cool Roof Central (U.S. Only) -
Learn about the leading energy-saving roofing options that can reduce your operating expenses and extend roof life. Available free at www.gaf.com.

Spec Central -
For architects and specifiers (or property owners with in-house design departments), Spec Central provides a wealth of information for writing roofing specs. Available free at www.gaf.com.

Architectural Information Services -
Architects and specifiers (or property owners with in-house design departments) can access an entire team devoted to the specification process. Available free by calling 1-800-522-9224.

Roof Protection Services -
Some roofing manufacturers allow their sales representatives to do the final technical inspection of your finished roof system. GAF, through Roof Protection Services, uses only experienced technical representatives for these inspections—for your protection!

* Securock® is a registered trademark of the United States Gypsum Company

** Dens Deck Prime® is a registered trademark of Georgia-Pacific Gypsum LLC.


All documents are U.S. English unless otherwise noted

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