The ultimate guide to specifying XP and eXP drywall products

When selecting building materials for high-performance commercial projects, mold- and moisture-resistant drywall is critical to the building’s long-term viability. Gold Bond Building Products, LLC, an affiliate of National Gypsum Company, offers two premium solutions: XP® gypsum boards and eXP® gypsum panels. While both provide superior protection compared to standard gypsum boards, their differences make them ideal for specific applications.

Let’s break down the key distinctions between XP and eXP products to help you choose the best option for your next project.

Understanding the core differences between XP and eXP

Both XP gypsum boards and eXP gypsum panels feature advanced resistance to mold, mildew and moisture. However, they differ in an essential way: the facer material.

• XP products feature a paper facer on both sides, which is ideal for interior environments that are subject to incidental moisture such as restrooms and kitchens.

• eXP products feature a coated fiberglass mat facer, providing superior moisture resistance and a 12-month exposure warranty.

“The difference comes down to exposure,” said Chris Whitmire, director of product marketing for National Gypsum. “XP means ‘extra protection,’ while eXP stands for ‘extra protection to extended exposure.’ eXP’s coated fiberglass mat facer gives you peace of mind during prolonged construction timelines.”

Selecting the right product for interior applications: XP Hi-Abuse vs. XP Hi-Impact

For high-traffic interiors, durability is just as important as moisture resistance — which is why specifying abuse-resistant drywall and impact-resistant drywall can help ensure walls withstand daily wear and tear, dents and penetrations.

“People often assume ‘abuse resistant’ and ‘impact resistant’ are interchangeable,” Whitmire explained. “However, there is a performance difference, as well as price difference. It's important to make a distinction between the two products"

XP® Hi-Abuse® and XP® Hi-Impact® gypsum boards deliver enhanced performance for demanding environments, but each is built for a different kind of performance.

• XP Hi-Abuse features a denser gypsum core and heavy-duty face paper for superior abrasion resistance. It’s ideal for hallways, lobbies, dormitories and schools — anywhere that is prone to surface abrasion.

• XP Hi-Impact goes a step further, with a fiberglass mesh embedded in the gypsum core to prevent penetration through the board. It’s perfect for hospital corridors, behavioral health facilities and stairs, where wall damage could compromise safety.

Pro tip: eXP® Interior Extreme® AR and eXP® Interior Extreme® IR gypsum panels provide fiberglass mat protection for these same high-abuse and high-impact interior environments when installation occurs before the building is fully enclosed or when prolonged exposure to moisture may occur during occupancy of the building.

Pre-rock applications: Choose eXP for protection you can count on

One of the most common specification challenges occurs during pre-rock or top-out construction phases, especially when timelines or budgets tempt teams to value engineer eXP for XP.

Here’s the problem: XP is not designed for exposure to the elements, and installing paper-faced products without appropriate weather protection is a code violation. Furthermore, when used too early — before the building is fully enclosed — it can result in facer delamination and material degradation.

“Contractors sometimes assume that being under a roof is enough,” Whitmire said. “But if the windows are not installed, that XP board is vulnerable to windblown rain and water pooling on floor slabs. Our eXP products are engineered to withstand this kind of exposure thanks to the coated fiberglass mat that is water and weather resistant.”

Choosing the right shaftliner

Shaftliner products are essential for fire-rated assemblies, including stairwells, elevator shafts and area separation walls between adjacent dwellings. These 1-inch-thick, 2-foot-wide panels are available in both XP and eXP versions.

• Shaftliner XP® is ideal for standard shaftwall systems once the building is enclosed or when the shaft is conditioned during occupancy.

• eXP® Shaftliner features a fiberglass mat facer designed for early-stage installation where moisture exposure is likely or prolonged.

“If you’re building cavity shaftwalls early and leaving them exposed for weeks or months, eXP Shaftliner helps safeguard your build and your budget from weather-related damage.” Whitmire said.

3 real-world examples: Why the right spec matters

Scenario 1: The hospital corridor misstep
An architect specified XP Fire-Shield gypsum board for a hospital corridor with frequent gurney traffic. The result? Repeated wall penetrations followed by costly repairs.

• Solution: XP Hi-Impact should have been specified from the start.

Scenario 2: The moisture mishap in multifamily
A contractor substituted XP Shaftliner for eXP Shaftliner in an area separation wall for a townhouse project, assuming the structure would be enclosed quickly. A rainy spring season delayed progress and the paper facer delaminated.

• Solution: eXP, which was initially specified, should have been used to prevent excessive moisture damage, which subsequently resulted in demo and replacement.

Scenario 3: Shaftliner shortcut in a high-humidity space
Shaftliner XP was installed in an open mechanical shaft before the building was enclosed. Extended moisture exposure compromised the integrity of the gypsum panels.

• Solution: eXP Shaftliner would have been the better option.

Gold Bond has the ideal gypsum board for every application

Whether you’re designing for impact resistance, fire safety or weather exposure, Gold Bond offers a high-performance solution.

Still not sure which product fits your application? Contact our technical experts at 1-800-NATIONAL® Construction Services team or your region’s construction design manager for personalized recommendations and support.

Specify with confidence. Select the optimal gypsum board the first time — and avoid costly callbacks.