High performance gypsum

All buildings are required to have a water-resistive barrier such as 15 pound felt though many also act as air barriers. Vapor retarders are required by code depending on region. The air and water barrier manufacturer will specify joint treatment. For the protection of the gypsum panels, it is not necessary to tape the joints prior to the application of the air and water barrier.

Air barriers are systems of materials designed and constructed to control airflow between a conditioned space and an unconditioned space. The air barrier system is the primary air enclosure boundary that separates indoor (conditioned) air and outdoor (unconditioned) air. Gypsum panels are considered air barriers. The International Building Code (IBC) defines the air barrier as a continuous plane. National Gypsum believes that taping the joints on the gypsum sheathing meets the intent of the building code for an air barrier. An exterior sheathing application taped will provide about 20 perms of protection without addressing the transitions.

Best practice for waterproofing applications includes properly detailing and installing flashing material.

No, the glass mat is vapor permeable. Our Gold Bond^® eXP^® Sheathing (1/2”) has a permeance of 22 perms and Gold Bond^® eXP^® Fire-Shield^® Sheathing (5/8") is 19 perms.

Gypsum abuse and impact panel products can have a shallower taper. It is imperative to have the tape coat pulled tight during application. A good quality primer and paint will also help better cover the tape joints.

It is recommended that all drywall products, including gypsum shaftliner, avoid exposure to temperatures exceeding 125° F for extended periods of time. See Gold Bond^® eXP^® Shaftliner for more details.

Any assembly directly exposed to the fire should be rebuilt. For fire-rated assemblies not exposed directly to the fire, it is always best to have a certified/licensed fire protection engineer or inspector assess the assembly and determine if it is still capable of performing as designed in a future fire.

The Gypsum Association document GA-225-2019 “Repair of Fire-Rated Gypsum Panel Product Systems” covers this topic in detail.

Yes, V497 has 1- and 2-hour options which are constructed from one side and fire-rated from both sides.

Low-slope roof systems are intended to be installed, be water-tight or completed each day. Properly installed gypsum roof coverboards, like DEXcell^® Roof Board, should not be exposed to moisture for any length of time. Ponding water on any gypsum board is not warranted.

Cut edges of fiberglass mat gypsum sheathing do not require treatment.

Yes, interior and exterior fiberglass mat gypsum panels can be exposed for 12 months if installed in a vertical application. Gold Bond^® eXP^® Interior Extreme can be hung on the interior before the building is dried in.

In the shower or tub surround, a code approved backer board (reference Table 2509.02 in the International Building Code) like Gold Bond^® eXP^® Tile Backer panels, PermaBASE^® Cement Board or other product approved for "wet" areas are used for tile or non-tile applications in a shower or tub area. Water-resistant gypsum board, other than the glass mat tile backer panels, cannot be used in the wet area, per code. Outside the wet area moisture-resistant paper or glass mat gypsum products can be used, including in ceiling applications. Gold Bond^® XP^® Gypsum Board or Gold Bond^® eXP^® Interior Extreme Gypsum Panels can be used in non-wet areas.

Abuse-resistant gypsum board products, Gold Bond^® XP^® Hi-Abuse^® Gypsum Board or Gold Bond^® eXP^® Interior Extreme AR Gypsum Panels, are abrasion or scratch resistant. Impact-resistant gypsum board products, Gold Bond^® XP^® Hi-Impact^® Gypsum Board or Gold Bond^® eXP^® Interior Extreme IR Gypsum Panels, are also abrasion-resistant but are designed to stop penetration of impact into the cavity of the wall. Impact products will stop a baseball bat. See ASTM C1629 for more information.

Yes, you can construct a framed, fire-rated wall on top of a rated CMU or concrete wall. There are no UL designs that show these two systems tested in conjunction.

Gypsum Association document GA-214-15 “Recommended Levels of Finish Gypsum Board, Glass Mat & Fiber-Reinforced Gypsum Panels” recommends skimming any glass mat interior product to a Level 5 finish in aesthetic areas and areas in critical lighting conditions. Gold Bond^® eXP^® Interior Extreme cuts and scores the same as paper faced gypsum board products.

Gypsum board products are manufactured the same if made with byproduct gypsum or natural (quarried) gypsum. There is no price premium for products made from byproduct gypsum. Byproduct gypsum raw material resources are only available where high-sulfur, coal-fired power plants are located and therefore not all manufacturing facilities have the access to this raw material, only those plants near a coal-fired power plant.

Since taping requirements are not uniform across UL designs, we do not include this information on the fire-rated images shown in the presentation. We recommend reviewing the specific UL design for taping requirements.

Refer to UL Design W419 for a 1-4-hr rate shaftwall assembly, constructed from one side.

Joints in glass mat sheathing panels are typically not treated and covered with a weather barrier. We recommend consulting your weather barrier manufacturer for any requirements they may have regarding treating the panel joints.

There are no compatible fasteners that work with both masonry and gypsum, and you can't rely on adhesive in tile applications. Furring strips should be applied to the masonry for the attachment of eXP Tile Backer or any gypsum board or panel.

Yes, interior and exterior fiberglass mat gypsum panels can be exposed for 12 months if installed in a vertical application. Gold Bond^® eXP^® Interior Extreme can be hung on the interior before the building is dried in.

No, the fiberglass mat is vapor permeable. Our Gold Bond^® eXP^® Sheathing (1/2”) has a permeance of 22 perms and Gold Bond^® eXP^® Fire-Shield^® Sheathing (5/8") is 19 perms.