Open Accessibility Menu

How to Build a Wildfire Resistant Deck: Essential Tips to Protect Your Property

A wildfire-resistant deck is essential for homeowners in fire-prone areas. Due to climate change, wildfire risks are escalating, which increases the importance of protecting your property. But how to build a wildfire resistant deck?

The first question to ask is, is there such a thing as a Fireproof deck?

The answer is that no typical decking material is truly fireproof. However, one can significantly reduce the risk as well as spread by using materials that carry significant superior fire resistance compared to traditional wood and composite decking.

One of the best ways is to get rid of an old wood deck (which is more likely to catch fire) and replace it with a more fire resistant one.

Besides, there are other things to do, like fuel modification and below-deck protection.

In this article, we will look into all these steps to build a wildfire resistant deck. We will also share some valuable tips to safeguard your valuable deck from a wildfire.

How to Build a Wildfire Resistant Deck

Knowing exactly which materials do not catch fire will help you a lot in picking the most fire resistant material for the deck. However, that’s not enough. You also need to know how to landscape in a way that makes sense. Let’s look into these considerations:

Choose These Five Fire Resistant Decking Materials

Fire resistant materials help protect decks from wildfires. However, they are not fireproof. This means that they can only withstand direct flames for a short time before igniting or becoming dangerously hot.

“The two main criteria to look for in building products are a Class A FSI (Flame Spread Index) and WUI (Wildland- urban Interface) compliance,” according to TimberTech, a composite decking specialist. A material's flame-spread, which describes how it burns on the surface, is one of the most tested properties for how well it holds up in a fire. WUI requires materials to resist flame spread, flying embers, and wildfire heat.

So it’s obvious that fire resistant materials are your best bet to fight wildfires. Here are the best materials for decking that are fire resistant:

  • Fire Retardant Treated (FRT) Wood: Fire-retardant treatments make wood fire resistant. These treatments are applied during manufacturing or to decks. They protect against embers. FRT wood also offers aesthetics. However, they need retreatment.
  • Composite Deck Boards: Fire resistant composite boards look like wood, but they do not leak or get wet. However, not all composite boards are fire resistant. Hence, you should check before buying. Composite boards are durable, low-maintenance, and rot-free. They are expensive at first, but they save money in the long run.
  • Autoclaved Aerated Concrete (AAC): AAC blocks are light, fire resistant, and non-toxic. They offer superior insulation and fire ratings. They are ideal for fire-prone areas but are more expensive due to the special installation requirements.
  • PVC: PVC decking, particularly the TimberTech Advanced PVC Vintage and Landmark Collections, has received the highest possible WUI and FSI Class A Flame Spread rating. That means TimberTech Advanced PVC Decking and Cladding now meets most building codes for materials that are fire-resistant. Better for fire areas, it is part of making a home's perimeter more secure, and it improves the home's look, value, and usefulness.
  • Steel Deck Framing: Steel deck frames mitigate fire risk. They support various decking materials, like composite, PVC, hardwood, etc. They also offer longer spans for creative designs. Besides, they last a long time, do not rot, are eco-friendly, and can hold heavy deck furniture.

Make the Space Near the Deck Fire Resistant

There needs to be a clear distance between the deck and potential fuel sources. To create and keep a clear zone, or defensible space, around your home, you need to control vegetation, which is also known as fuel modification. The International Wildland-Urban Interface Code (IWuIC) says that the minimum fuel modification distance should be 30 feet in moderate fire-hazard areas. It should be 50 feet and 100 feet, respectively, in high and extreme fire-hazard areas.

Here are some more things you can do to make the area around the deck less likely to catch fire:

  • Keep firewood and other things that can catch fire away from the deck and out of the way.
  • Put a layer of stones on the ground below and around the deck.
  • Clean up the hard-to-reach areas of decks that are close to the ground by removing pine straw, dried leaves, and tree branches.
  • Isolate your home and deck from nearby plants with flagstone patios, gravel paths, and masonry retaining walls.
  • Get rid of any dead trees, grass, plants, or grasses, and any plants that could catch fire near decks.
  • Leave at least 10 feet of space between trees, and cut back any branches that hang over the deck by at least 6 feet.

Below-Deck Protection

The IWuIC requires additional fire protection for decks constructed above terrain that slopes downward and away. Besides, local jurisdictions may require below-deck enclosures. For example, if any part of an attached deck sticks out over a slope that drops more than 10%, the space below it needs to have fire resistant walls on the outside.

The walls must also be at least 6 inches from the ground and can be constructed in a number of different ways. Noncombustible walls made of brick, stone, or concrete block work well, but they require footings. You can ask your deck builders to build stud walls that hang from the deck and have one-hour fire-resistance-rated assemblies on the outside.

For example, using metal studs with type-X gypsum sheathing and fiber-cement siding or cement stucco on top can be an option. Also good are walls that are faced on the outside with materials that will not catch fire, like FRT wood siding. Heavier-timber or log walls are also acceptable, though they may not be as common.

Of course, if your deck boards have gaps between them, you need to make sure that the enclosed area can drain and breathe. Because of this, the walls can be opened up to 6 inches below the ground.

If you are concerned about the empty space below, consider a waterproof deck with a concrete slab and fire-resistant walls. This solution not only addresses drainage concerns but also enhances fire protection for your deck Your drainage problem is fixed, and you are safe from below now.

If you need to ventilate the space, use wall vents that are designed to keep embers and flames out.

Protecting Decks from Wildfires

Smart landscaping choices, fire resistant building materials, and taking precautions can all help a deck survive a wildfire. Along with the ones discussed above, these other safety measures can help keep homes and decks safe:

  • Cover exposed wood with finishes that do not catch fire.
  • Make sure that several deck exits lead away from homes.
  • Keep ABC fire extinguishers close by to put out small fires outside.
  • Before the fire season, bring flammable patio furniture inside.

Is Fire Resistant Decking Worthwhile?

Fire resistant decking costs more to install at first. However, it protects people in wildfire-prone areas for years by not catching fire. Flame-retardant lumber, fire-rated composite boards, and nonflammable concrete all help prevent threatening deck fires.

Along with lowering the risk of fire, fire resistant decks also raise the value of the home. The long-term benefits of fire-resistant decking for homes in fire zones justify the initial extra cost. Consult with qualified deck builders for tailored recommendations on the most suitable fireproof decking options for your specific space.


Q. What Decking Material Has the Greatest Fire Resistance?

Ans. Autoclaved aerated concrete (AAC) has one of the best fire ratings of all deck materials. These light concrete blocks can withstand direct flames and high temperatures for a long time.

Q. When is Fire Resistant Decking Mandated?

Ans. In areas with a high risk of fire, elevated decks and porches must use materials that are resistant to ignition.

Q. Can Wood Deck Boards be Used in Fire-Prone Areas?

Ans. Yes, as long as the wood is treated with a fire retardant that is approved for areas that are near wildlands and cities. FRT wood is highly resistant to ignition while remaining cost-effective and workable.

Q. What is Fire-Rated Decking?

Ans. Fire rating shows how well a substance stops fire from spreading. Fire ratings are given on a scale from A to C, with A being the least likely to catch fire. Standardized tests that measure flame spread are what determine these ratings.

Here’s how it works:

  • Class A Flame Spread: The most fire resistant.
  • Class B Flame Spread: Exhibits high flame resistance.
  • Class C Flame Spread: Offers moderate flame spread resistance.


You can start building a wildfire resistant deck by picking out materials that will not catch fire. FRT wood, composite deck boards, AAC blocks, and steel framing are some of these. These materials are not fireproof, but they can handle flames to a great extent.

Besides, it is important to keep the area around the deck clear and manage the plants to make it safe to defend. Extra fire protection, like fire resistant walls, is needed for the area below the deck, especially if it is on a slope. Finally, safety measures like fire extinguishers and nonflammable finishes can help protect decks from wildfires.

If you want to build a deck that can withstand wildfire, Archadeck can help. First, our experts will make a plan for what you want that includes everything you want. Then, our contractors will use only the best materials to build your custom structure. Contact us today to get your dream deck.