Glass Mat Gypsum Sheathing for Exterior Walls: Uses & Test Data

Our fiberglass mat-faced gypsum board is designed for exterior wall sheathing, commercial buildings, residential construction and other applications that require a durable, moisture-resistant and fire-resistant substrate.

The board is manufactured with a moisture-resistant gypsum core reinforced by inorganic fiberglass mat facers. This paper-free construction provides improved resistance to moisture, swelling, warping, surface deterioration and facer delamination compared with traditional paper-faced gypsum board.

It provides a stable substrate behind exterior cladding systems such as EIFS, stucco, brick veneer, stone veneer, fiber cement siding, metal panels and rainscreen systems.

Product Structure

The board consists of:

• Moisture-resistant gypsum core
• Inorganic fiberglass mat facer
• Reinforced surface for improved durability
• Stable and uniform panel structure
• Paper-free construction for demanding environments

The fiberglass mat helps improve surface durability and reduces the risk of damage caused by humidity and moisture during exterior wall construction.

Key Features and Benefits

Moisture-Resistant Exterior Sheathing

The moisture-resistant gypsum core helps reduce water absorption, swelling and dimensional changes. It is suitable for exterior wall applications and moisture-prone construction environments.

The board is designed to maintain its performance when used as part of a properly designed exterior wall assembly.

Durable Fiberglass Mat Facers

Unlike traditional paper-faced gypsum board, this product uses inorganic fiberglass mat facers. The glass mat provides a durable surface that helps resist tearing, delamination and deterioration during handling and installation.

Stable Substrate for Exterior Cladding

The board provides a flat and durable base for a wide range of exterior cladding systems, including:

• EIFS
• Stucco
• Brick veneer
• Stone veneer
• Fiber cement siding
• Metal wall panels
• Exterior decorative panels
• Rainscreen cladding systems

It can help contractors create a stable substrate before installing the final exterior finish.

Mold and Mildew Resistant Design

The inorganic fiberglass mat does not provide the same organic paper surface found on traditional paper-faced gypsum boards. This design helps reduce the risk of mold and mildew growth in humid and moisture-prone environments.

For projects requiring a specific mold-resistance rating, additional testing and technical documentation can be provided upon request.

Fire-Resistant Gypsum Core

Gypsum is widely used in fire-resistant building systems because of its mineral core and fire performance. Our fiberglass mat-faced gypsum board can be used in exterior wall assemblies where fire performance is an important design consideration.

The fire resistance of a complete wall system depends on the framing, fasteners, number of board layers, joints, insulation and exterior cladding system.

Reduced Swelling and Warping

The reinforced construction helps improve dimensional stability and reduce the risk of warping, sagging, buckling and surface deformation. This provides a more reliable base for exterior cladding installation.

Good Mechanical Performance

The board offers reliable bending strength, impact performance, shear strength and screw-holding capability. These properties make it suitable for demanding wall assemblies and commercial construction projects.

Efficient Handling and Installation

The board can be supplied in different sizes and thicknesses according to project requirements. Its gypsum-based structure allows efficient cutting, handling and installation using common exterior wall construction methods.

Installation should follow the requirements of the selected wall system, including framing, fasteners, joint treatment, flashing, weather-resistant barriers and exterior cladding.

Applications

Fiberglass mat-faced exterior gypsum sheathing board is suitable for:

Renovation and building refurbishment projects

Exterior wall sheathing

Residential buildings

Commercial buildings

Industrial buildings

Hotels and office buildings

Schools and hospitals

EIFS wall systems

Stucco wall systems

Brick and stone veneer systems

Fiber cement and metal siding systems

Exterior soffits and overhangs

Moisture-prone construction areas

Technical Data from Test Report

The following information is based on the available test report for the tested sample.

Test item	Reported result	Reported criterion or note
Appearance	Conforming	No defects affecting use were reported
Length deviation	-1 mm	-4 to 0 mm
Width deviation	-2 mm	-4 to 0 mm
Thickness deviation	-0.2 mm	±0.2 mm
Diagonal length difference	2 mm	≤ 4 mm
Surface density	10.5 kg/m²	Reported as measured data
Breaking load, longitudinal	Average 680 N; minimum 633 N	Average ≥ 530 N; minimum ≥ 470 N
Breaking load, transverse	Average 434 N; minimum 410 N	Average ≥ 210 N; minimum ≥ 190 N
Hardness	End 268 N; edge 241 N	≥ 100 N
Impact resistance	No radial crack on the back after impact	Conforming to the report criterion
Face mat/core bond	No delamination	Conforming to the report criterion
Water absorption	4%	≤ 5%
Fire stability	> 60 minutes	≥ 60 minutes
Wet deflection	1 mm	≤ 6 mm
Shear force	570 N	≥ 320 N
Radionuclide limits	IRa 0.0; Iγ 0.0	Each ≤ 0.6
Screw pull-out resistance	370 N	Reported as measured data
Formaldehyde emission	Not detected at 76 hours	Report lists ≤ 0.025 mg/m³, ENF criterion

The test results apply to the tested sample under the conditions stated in the report. Actual performance may vary according to product thickness, production batch, installation method and wall assembly design.

Exterior Wall System Compatibility

For reliable long-term performance, the board should be installed as part of a complete exterior wall system. The system may include:

• Wood or steel framing
• Fiberglass mat-faced gypsum sheathing
• Joint treatment
• Flashing and drainage details
• Weather-resistant barrier
• Air barrier
• Thermal insulation
• Exterior cladding

The board provides moisture resistance and a durable sheathing substrate. It is not intended to replace the complete waterproofing, flashing or drainage design of an exterior wall system.

Custom Sizes and Supply Options

We can discuss project-specific requirements for:

• Board thickness
• Panel dimensions
• Edge type
• Surface color or marking
• Packaging method
• Pallet packing
• Container loading
• OEM production
• Bulk export orders

Please contact us with your required thickness, panel size, application, quantity and destination port.

Frequently Asked Questions

Is fiberglass mat-faced gypsum board suitable for exterior walls?

Yes. It is designed to be used as an exterior wall sheathing board behind cladding systems such as EIFS, stucco, brick veneer, stone veneer, siding and rainscreen systems.

What is the difference between fiberglass mat-faced gypsum board and paper-faced gypsum board?

Fiberglass mat-faced gypsum board uses inorganic fiberglass mat facers instead of paper. This improves moisture resistance, surface durability and resistance to delamination in demanding environments.

Can the board be used in humid conditions?

Yes. The moisture-resistant core and fiberglass mat facers make it suitable for humid and moisture-prone construction areas. Proper joint treatment, flashing, weather barriers and exterior cladding are still required.

Can the board be customized?

Yes. Sizes, thicknesses, packaging and other supply requirements can be discussed according to the project specification and order quantity.

Can you provide technical documents and samples?

Yes. Product samples, test report information, technical specifications and export quotations can be provided according to customer requirements.

Request a Quote

Looking for a reliable fiberglass mat-faced gypsum board supplier for your exterior wall project?

Send us your required:

• Board thickness
• Panel size
• Quantity
• Exterior cladding type
• Application
• Destination port

Our team will recommend a suitable product specification and provide a quotation for your project.mat gypsum sheathing, contact our team with your project location, wall framing type, exterior cladding system and required board dimensions. We can help confirm which product details and technical documents should be reviewed for your application.

View product details: Fiber-Reinforced External Gypsum Board