Using Gypsum Tile Backer Boards in Moisture-Prone Areas
A surge in mold remediation cases in construction over the past decade has inspired gypsum board manufacturers to develop a variety of moisture- and mold-resistant products to combat mold growth. Included in this growing range of high-performance, moisture-resistant products are gypsum tile backer boards with glass mat facings - products which present a variety of benefits to tile contractors, as well as end users.
BackgroundGypsum manufacturers first utilized glass mat technology on exterior sheathing products, in order to provide structures better protection from moisture damage during construction. Following positive results in this application, manufacturers began using glass mats on shaft liners, tile backers and interior gypsum boards as an alternative to traditional paper facing, which can delaminate or become a food source for mold if exposed to moisture for too long.
Fiberglass Glass mat technology involves embedding fiberglass mats into a treated, moisture-resistant gypsum core. The glass mat gypsum boards, commonly referred to as paperless gypsum, have additional coatings applied to the side that the tile is adhered to. These coatings provide a reduced vapor transmission or perm rating and a reduced surface water absorption value - items needed for wet area applications. In addition, they include a texturing agent, providing a rougher surface, and strengthen the adhesive bond between the tile backer and the tile. Together, these ingredients provide a strong defense against moisture and mold growth.
Enhanced Moisture and Mold ResistanceThe combination of the vapor-retardant coating over the glass mat creates a moisture-resistant surface that inhibits water vapor permeance. Fiberglass is naturally moisture-resistant and is an inorganic material, which makes it resistant to mold growth. By warding off excess moisture with embedded fiberglass and eliminating a mold food source, paperless gypsum tile backers greatly decrease the possibility of mold growth in the wall assembly. For top performance, look for tile backer boards that meet or exceed the specifications of ASTM C 1178, Standard Specification for Coated Glass Mat Water-Resistant Gypsum Backing Panel and ASTM D 3273, Standard Test Method for Resistance to Growth of Mold on the Surface of Interior Coatings in an Environmental Chamber.
Increased DurabilityEmbedded glass mats fortify gypsum tile backer boards, making them durable and dimensionally stable, as well as resistant to delaminating, rippling, buckling and sagging caused by environmental conditions, such as changes in temperature or relative humidity. These glass mat-reinforced tile backers will provide a flat and uniform substrate for all tile applications, including bathtub and shower walls, bathroom floors, and kitchen countertops.
In addition to strong performance after installation, glass mat gypsum tile backer boards offer a variety of benefits during installation for contractors.
Easier to Handle and InstallContractors can handle and install glass mat gypsum tile backer board in the same way they would standard paper-faced gypsum board. They are lighter than conventional cement tile backer and fiberglass-related skin irritations are minimized, as the mats are fully embedded. And, unlike conventional cement tile backer, glass mat gypsum tile backer board does not need to be cut with power tools; it can be scored and cut with a standard utility knife. The glass mat gypsum board snaps free after only one face is scored. This cuts down on the amount of particle dust expelled into the air.
Embedded glass mat gypsum tile backer boards attach to framing with standard fasteners designed for tile backer applications and have uniform field and edge hardness, making the trimming and fastening process quick and easy. Being able to trim and fasten more quickly allows contractors to reduce the occurrence of overdriven fasteners in a board. Finally, installing glass mat gypsum tile backers saves contractors a step, as conventional cement tile backers require a vapor barrier to be installed behind the tile backer. Since the glass mats provide the needed moisture protection, no vapor barrier is needed.
All of these factors combined lead to a smoother tile backer installation that saves time and money.