Approved Uses for Gypsum Classified Roof Cover Boards

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One concern that often arises when determining the scope of work for a particular project is determining which cover boards are approved with Garland roof systems and in what applications can they be applied.  As shown in Table 1, there are three gypsum cover boards that are approved, which include DensDeck Prime, DensDeck DuraGuard and Securock (See Figures 1 , 2 , and 3 for illustrations). All three cover boards are applicable in cold, hot, torch and self-adhering systems.  However, caution must be taken when applying DensDeck DuraGuard and DensDeck Prime in hot asphalt, as flood mopping directly to a substrate followed by a flood mopped application of a membrane, also known as full encapsulation, is not recommended.

APPROVED ROOF BOARDS (Table 1)

Manufacturer

Product

Application

Cold

Hot

Self-Adhering

Torch
USG Securock

✓

✓

✓

✓
Georgia-Pacific DensDeck

Prime

✓

✓*

✓

✓
Georgia-Pacific DensDeck

DuraGuard

✓

✓*

✓

✓
* Not Recommended For Full Encapsulation in Hot Asphalt

Along with roof applications there are times when other gypsum based wall boards may be specified by an architect or installed by a contractor.  Table 2 shows two examples of gypsum based wall boards, Gold Bond exp and DensGlass (See Figures 3 and 4 for illustrations).  When attaching either of these boards to the outside of sidewall and soffit framing, caution must be taken due to their physical properties, as both products are not recommended for application in hot or self-adhering systems.

APPROVED WALL BOARDS FOR FLASHING (Table 2)

Manufacturer

Product

Application

Cold

Hot

Self-Adhering

Torch
NGC Gold Bond exp

✓

N/A

N/A

N/A
Georgia-Pacific DensGlass

✓

N/A

N/A

N/A

If DensGlass or Gold Bond exp is specified on surrounding walls where flashing attachment is required in applications other than cold process, there are two actions that can be taken to avoid any problems with adhesion to the cover board:

  1. Overlay approved roof board from Table 1
  2. Remove wall board and install approved roof board from Table 1

Contact your local Garland representative to learn more!