Hardening Decks & Secondary Structures with Wildfires in Mind

Decks, patios, sheds, and other secondary structures are particularly vulnerable to wildfires. Made from combustible materials, they can act as fuel for approaching flames and increase the risk of fire spreading to your home. By making strategic upgrades and maintenance decisions, you can harden these structures against wildfires, helping to keep your property and home safer.

This article provides practical tips on reinforcing decks and secondary structures, minimizing ignition risks, and implementing fire-resistant practices.

Choosing Fire-Resistant Deck Materials

Many decks are built from wood, which is highly combustible and prone to ignition from embers. Upgrading to fire-resistant materials can significantly reduce the risk of your deck catching fire and spreading flames to your home.

Composite Decking: Look for fire-resistant composite decking materials that contain a mix of plastic and wood fibers. Some composite decking products are specifically designed to be fire-resistant and are less likely to ignite compared to traditional wood. Be sure to verify the Fire Rating of any composite material you choose.
Metal Decking: Metal decking, such as aluminum or steel, is non-combustible and provides excellent fire resistance. Metal decking can be paired with other fire-resistant materials to create a safe, durable deck structure.
Fire-Treated Wood: If you prefer the look of wood, consider using fire-treated wood. This wood is chemically treated to resist ignition and has a higher tolerance to heat and flames than untreated lumber. Keep in mind that fire-treated wood may require periodic reapplication of fire retardants to maintain its resistance.
Paving Stones and Concrete: For maximum fire resistance, consider building a deck from non-combustible materials like concrete or paving stones. These materials are not only durable and fire-resistant but also provide an attractive alternative to traditional wood decking.

Deck Design Strategies for Fire Resistance

Beyond material choice, certain design strategies can help minimize your deck’s vulnerability to wildfires.

Enclose the Underside: The area beneath a deck is often exposed to dry leaves, pine needles, and other debris that can easily catch fire. Enclose this space with non-combustible materials like fiber cement, metal mesh, or Masonry to prevent debris accumulation and ember intrusion.
Install Skirting: Skirting is a solid barrier that surrounds the perimeter of your deck. By using fire-resistant skirting materials like metal or cement board, you create an additional barrier that blocks embers from reaching the underside of the deck.
Limit Gaps Between Deck Boards: If you’re constructing a new deck, install the boards with minimal spacing between them to reduce gaps where embers could lodge. If you’re retrofitting an existing deck, consider adding a fire-resistant overlay or deck board spacers to close the gaps.
Install Ember-Resistant Vents: If venting is necessary for airflow beneath the deck, use ember-resistant vents with a fine metal mesh. This will allow Ventilation while preventing embers from entering and igniting materials stored below the deck.

Maintaining a Fire-Resistant Deck

Regular maintenance is essential for keeping your deck fire-resistant. Routine upkeep reduces the risk of ignition and extends the lifespan of your deck materials.

Clean Regularly: Sweep away leaves, pine needles, and other debris from your deck’s surface and underneath. Accumulated debris can act as Kindling and ignite from embers, especially during dry and windy weather.
Inspect for Damage: Check for any cracks or damage in the decking material. Damaged areas may be more prone to catching fire, so replace any compromised boards or sections promptly.
Reapply Fire-Retardant Treatments: If your deck materials are treated with fire-retardant coatings, reapply them according to the manufacturer’s recommendations. This will help maintain their effectiveness over time and enhance the deck’s resistance to flames.

Protecting Sheds, Pergolas, and Other Secondary Structures

Secondary structures such as sheds, pergolas, and playhouses are often built with wood or other combustible materials. Reinforcing these structures helps prevent them from contributing to fire spread.

Choose Fire-Resistant Materials: When constructing sheds, pergolas, or other secondary structures, consider using fire-resistant materials like metal, stone, or concrete. If wood is necessary, use fire-treated lumber or add a fire-retardant coating.
Install Metal Roofing: Metal roofing is non-combustible and can help protect secondary structures from embers and radiant heat. Install metal roofing on sheds and other structures to improve their fire resistance and reduce the chance of ignition.
Add Fire-Resistant Siding: Fiber cement or Stucco siding is a great choice for secondary structures, as it’s non-combustible and durable. Fire-resistant siding helps shield these structures from heat and flames, providing additional protection for your property.
Create a Defensible Space: Clear a defensible space around secondary structures by removing dry grass, leaves, and any other Flammable material within at least 5 feet of the building. This area acts as a buffer zone, helping to prevent flames from reaching the structure.

Safe Storage and Fire-Resistant Landscaping

The area around your deck and secondary structures can also influence their susceptibility to fire. Creating a fire-resistant landscape and using safe storage practices are key components of a comprehensive wildfire defense strategy.

Store Combustible Items Safely: Store items like firewood, propane tanks, and fuel containers away from decks, sheds, and other structures. These materials should be kept at least 30 feet from your home or secondary structures to reduce fire hazards.
Use Non-Combustible Ground Cover: Instead of using wood Mulch around decks and sheds, opt for Gravel, rocks, or Pavers. Non-combustible ground cover helps reduce the chance of fire spreading to the structures and keeps embers from finding fuel near them.
Plant Fire-Resistant Vegetation: Select fire-resistant plants for the area around your deck and secondary structures. Avoid plants with resinous or oily foliage, which can ignite easily. Maintain a defensible space by keeping plants well-spaced, trimmed, and free of dead material.

Additional Resources

For more information on fire-resistant building materials and landscaping practices for decks and secondary structures, consult the following resources:

Firewise USA Program: Firewise USA provides resources for homeowners in wildfire-prone areas, including guidelines on fire-resistant building materials and defensible space. Visit the Firewise USA Program for more details on wildfire preparedness.
California Department of Forestry and Fire Protection (CAL FIRE): CAL FIRE offers a variety of tips and recommendations for hardening homes and outbuildings against wildfires. Visit Ready for Wildfire for information on creating defensible space and wildfire safety.
CalFire: The California Department of Forestry and Fire Protection has live maps to track wildfires and advice on prevention measures. Highly recommended resource: https://www.fire.ca.gov/

Wrap-Up

By reinforcing your decks and secondary structures with fire-resistant materials, maintaining clear areas around them, and implementing safe storage practices, you can greatly reduce the risk of wildfire damage. These steps help prevent flames from spreading to your home and improve the resilience of your property. Taking the time to prepare and maintain these structures not only increases their longevity but also contributes to the overall safety of your home and family.

With the right materials, design strategies, and maintenance, your decks and secondary structures can withstand the challenges of wildfire season, protecting your home and providing peace of mind.