When building in fire-prone areas, a deck isn’t just a nice-to-have backyard feature— it becomes a part of the home’s first line of defense against wildfire. So, how do you make a deck fire-resistant? In an article in Professional Builder, Steve Hawks, senior director for wildfire at the Insurance Institute for Business & Home Safety (IBHS), lists seven ways to design a wildfire-prepared home. When it comes to deck construction, Hawks’ recommends “upgrading to noncombustible posts, joists and walking surface materials to reduce the chances of ignition below and on top of the deck.”

These deck upgrades make perfect sense. After all, a deck built with noncombustible components can help slow down or even stop fire from spreading to the structure it’s attached to, significantly lowering the risk posed to the property and surrounding areas. Looking closely at Hawks’ list of recommended deck upgrades, it’s clear the deck framing material plays a crucial role in fire protection. Because even if you use fire-resistant decking, fire can still spread to the house if the substructure is made of a combustible building material like wood. That’s why the deck substructure is arguably the most important part of any fire-smart outdoor space.

So, what’s the best fire-resistant deck framing material out there? Steel—hands down. Let’s break down why.

Comparing steel deck framing vs. wood deck framing

Unlike wood, which can act as fuel in the event of a fire, steel is inherently noncombustible, ignition-resistant and fire-resistant. In turn, a steel deck framing system will not ignite, feed flames or weaken under intense heat the same way traditional wood deck framing does. Even fire-retardant-treated (FRT) wood, which is marketed as a fire-safe option, requires ongoing upkeep to maintain its fire performance. Plus, FRT can be difficult to source, expensive and bulky to work with. It can also become brittle over time and the treatments can alter the material’s load-bearing capacity. Additionally, as a natural building material, wood is vulnerable to rot and deterioration after long-term exposure to moisture.

On the other hand, noncombustible steel deck framing is incredibly durable and does not need any fire-retardant coatings to do its job. It performs as intended from day one and keeps doing so throughout its service life. For builders, that means fewer callbacks and ultimate peace of mind that the deck you built for your client will stand up to whatever Mother Nature throws at it.

Steel deck framing paired with fire-resistant decking is a code-compliant choice

To mitigate damages to life and infrastructure from wildfire events, many municipalities across the country have adopted Wildland-Urban Interface (WUI) building codes and National Fire Protection Association (NFPA) 1144 codes. These particular building codes require that contractors build a one-hour fire-resistant assembly (this includes the decking, framing and house siding) to minimize ignition hazards and reduce the risk of fire spread.

Because steel deck framing is noncombustible and fire-resistant, it can be used under fire-resistant decking to create a code-compliant, fire-resistant deck structure from the ground up. In fact, Hawks highlights that in states like California and Oregon, meeting these codes can even help homeowners “receive a designation that can be used to discuss coverage and possible incentives with insurers.” That can be a major selling point for builders during the bidding process.

Evolution steel deck framing system delivers tested fire performance

Leveraging steel’s proven fire performance, the Evolution steel deck framing system from Fortress Building Products is a fire-resistant, flame-resistant and ignition-resistant solution. Underscoring its safety factor, Evolution received a Class-A fire-resistant rating after completing the ASTM E84-21a, Standard Test Method for Surface Burning Characteristics of Building Materials. This designation means homeowners investing in Evolution can meet WUI building codes, NFPA 1144 codes and the strict California Chapter 7A requirements. Evolution was also recently added to the California Fire Safe Council's Fire Safe Vendor List, which is one more reason to trust the deck framing system in states with high wildfire risk. 

The type of deck framing you recommend to your customers matters—especially in fire-prone areas. When it comes to designing a resilient and fire-hardened backyard, a steel deck framing system stands above the rest. Count on Fortress Building Products to provide smart, sustainable deck framing solutions that help you deliver fire-safe outdoor living spaces, no matter which part of the country your next project is located in.