Yes, Durock is an effective and code-approved heat shield, but it depends heavily on what you are shielding and your installation method.
(15.9 mm) Durock Cement Board panels are Underwriters Laboratories Inc. (UL) Classified for fire resistance, and may be used in any UL Design where Type DCB panels are listed.
By using an approved heat shield system, the required distance between the stove and adjacent wall can be significantly reduced. PermaBASE® Building Products are the industry-preferred choice and the only cement board approved for heat shield applications.
The "best" heat shield material depends entirely on your application, but generally, Aluminized Fiberglass and Aerogel are the top choices for automotive and industrial uses, while Ceramic Matrix Composites (CMCs) reign supreme in aerospace. The right material balances heat reflectivity, thermal insulation, and physical durability.
The edges are formed smooth. The ends are square cut. In cold weather and during USG Durock® cement panel and tile installation, temperatures within the building shall be maintained within the range of 40 to 100°F. Adequate ventilation shall be provided to carry off excess moisture.
Both Durock and HardieBacker are high-quality tile backer boards designed to prevent moisture damage and provide a solid foundation for tile. Choose Durock for ultimate moisture resistance and wet areas, or HardieBacker for easier cutting, less mess, and a stiffer board that yields flatter walls.
DuROCK Vapour Block is formulated with a co-polymer styrene-butadiene emulsion. It is a trowel applied high performance coating, applied onto non-combustible substrates as an air, vapour, and moisture barrier for DuROCK PUCCS and InsulROCK Systems.
Heat shield thickness generally ranges from 𝟎.𝟎𝟐 𝐢𝐧𝐜𝐡𝐞𝐬 (𝟎.𝟓 𝐦𝐦) to 𝟎.𝟓 𝐢𝐧𝐜𝐡𝐞𝐬, depending on the application. The most common varieties include reflective metal sheets, thermal blankets, and composite barriers.
NASA uses a variety of advanced, lightweight materials for spacecraft heat shields, tailoring the choice based on the speed of atmospheric entry and heat severity.
The most heat-resistant materials on Earth are a class of refractory ceramics called hafnium carbonitride (HfCN) and tantalum carbide (TaC). These compounds can endure extreme temperatures exceeding 4000∘C4000 raised to the composed with power C4000∘C (7232∘F7232 raised to the composed with power F7232∘F), making them the highest melting-point substances known to science.
Cement backer board is much heavier than other materials such as drywall or plywood. This makes it more difficult to transport and install, especially for walls and ceilings. Because cement backer board is heavier, more support may be required during installation, increasing the overall labor and time.
To fireproof the wall behind a wood stove, construct a proper wall shield that includes a minimum 1" vented air gap between the wall and the shield. Use non-combustible materials like sheet metal (e.g., 24-gauge steel), brick, stone, or ceramic tile mounted over a cement backer board.
Cement board and Type X or Type C fire-rated drywall offer different approaches to fire safety. Cement board is entirely non-combustible but transmits heat. Fire-rated drywall is designed to absorb heat and delay flames for 1 to 4 hours.
The industry's solution for heat shields
PermaBASE cement boards are the industry-preferred choice. Installation-ready and easy-to-use, PermaBASE® cement boards eliminate the need for field fabrication, saving time while allowing for enhanced performance and wood-burning stove placement closer to the wall.
Use 14one-fourth14-inch cement board exclusively for floors and countertops where it is fully supported by a solid subfloor. Use 12one-half12-inch cement board for walls, showers, and tub surrounds, as it is rigid enough to span the gaps between wall studs.
Interestingly, fiber cement is more sensitive to moisture (relative humidity) than to temperature. When it is very humid, the cellulose fibers inside can absorb microscopic amounts of moisture, causing the plank to expand slightly. In dry, hot weather, it may shrink.
Aluminium high thermal conductivity and a low emissivity rate makes it one of the best radiant heat shield. It is radiated heat that a shield has to screen, not conductive heat. With an air gap at the back of the shield, of course.
Aerogel, known as the "world's best insulating solid material," is used to enhance the thermal performance of energy-saving materials and sustainable products for buildings, on-and off-shore industrial infrastructure and consumer products.
The tiles on SpaceX's Starship are its heat shield, keeping it safe from the blazing 2,600°F temperatures during reentry. These ceramic hexagons are tough and built to last.
A broken or missing heat shield can lead to overheating, increasing the risk of a fire, especially when parked near flammable materials. Excessive heat can damage sensitive components like wiring, fuel lines, and brakes, leading to costly repairs if ignored.
To protect combustible walls behind a wood-burning stove, you should use non-combustible, heat-resistant boards such as cement board (like Durock or HardieBacker), perlite board, micore board, or prefabricated UL-listed Type 2 stove boards.
The best metal for a heat shield depends on your temperature needs: Aluminum is best for reflecting radiant heat, Stainless Steel is ideal for durability and structural strength, and Inconel is the top choice for extreme, high-performance environments (like turbochargers).
For most interior applications, Durock® Brand Cement Board Panels are not affected by water and do not need to be waterproofed. Durock® is water durable but not waterproof. If you're looking for added protection to water sensitive material behind the Durock®, you may consider adding a waterproofing membrane.
The side of Durock with the tag is the rough side. The other side goes to the wall.
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