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Building Upgrades for Added Wildfire Protection
Level Up for Heat & Flames – Your wildfire protection journey doesn’t end with ember-focused Critical Prep. Before heat and flame exposure become a threat, add protection by upgrading key building features and enhancing defensible space within 30 feet.
Your choices matter – Incorporate these upgrades during new construction for the greatest cost savings and add them during major exterior renovations for strong results. Proactive, research-based actions reduce your building’s wildfire risk for years to come.
Building Upgrades
These steps build on Critical Prep with key improvements that help structures withstand intense heat and flames. Upgrading building materials and enhancing defensible space within 30 feet, work together to reduce ignition risk when wildfire conditions escalate.
Wildfire Ready Business Guide
Know what steps will significantly improve the likelihood of your building’s survival.
Step 4: Level Up: Upgrade Key Building Features to Help Withstand Heat & Flames
With ember vulnerabilities addressed, strengthen key building features with materials that resist radiant heat and direct flames, which is essential when wildfire intensity and exposure increase.
1. Enclose Underside of Steep-Slope Roof Eaves and Overhangs
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- Enclose or “box in” open eaves and roof overhangs by covering the underside using noncombustible soffit materials, such as fiber-cement, stucco over a noncombustible backer, metal panels, or exterior-grade gypsum board (rated for exterior use). This should fit tightly between the fascia and exterior wall with sealed seams.
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- If adding vents needed for airflow, install flame- and ember-resistant vents with proper sealants or cover all openings with 1/8-inch metal mesh.
2. Upgrade Skylights
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- Replace domed, plastic skylights with flat, multipaned tempered glass models.
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- If operable, protect the opening with 1/8-inch metal mesh screening.
3. Cover Gutters with Noncombustible Guards
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- Install noncombustible gutter covers to reduce debris accumulation and maintenance.
4. Upgrade Windows
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- Replace all exterior windows with units featuring at least 2 panes of tempered glass, verified by visible corner etching on both panes. Glass blocks are also a fire-resistant option.
5. Upgrade Exterior Commercial Doors
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- Use solid-core exterior doors constructed with noncombustible or ignition-resistant materials like steel, fiberglass, or solid hardwood, and include a metal threshold.
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- Ensure any doors with glass panels use dual pane tempered glass with visible corner etching on both.
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- Alternatively, add a noncombustible storm door as a protective outer layer.
6. Install Noncombustible Wall Cladding (siding)
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- Select cladding made from noncombustible materials that meet ASTM E136 standards, such as fiber-cement, brick, stucco, metal, concrete, or masonry veneer.
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- Avoid combustible cladding made of vinyl, wood, engineered wood, or other wood-based materials – even those labeled “ignition-resistant” by construction or assembly. These materials remain combustible under extreme wildfire conditions.
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- Ensure any attached business signage is also constructed from noncombustible materials.
7. Build Noncombustible Building Attachments (e.g., decks, ramps, patios, balconies, awnings)
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- For New Attachments: Use steel framing, solid (no gaps) noncombustible decking surface materials, such as aluminum, porcelain tile, or concrete.
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- For Existing Combustible Attachments:
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- Replace combustible walking surface and stairs with solid (no gaps), noncombustible decking surface materials, such as aluminum, porcelain tile, or concrete.
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- Use noncombustible hand railings within the first 5 feet of the building.
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- Apply 6 vertical inches of noncombustible material (e.g., metal flashing or fiber-cement board) at the base of all combustible posts and stairs.
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- Enclose undersides of elevated attachments 4 feet or lower with 1/8-inch metal mesh to prevent ember intrusion.
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- Continue to maintain a 0–5 Foot Noncombustible Zone around all sides of the attachment and connected stairs.
Step 5: Level Up: Enhance Defensible Space to Help Protect from Heat & Flames
After reinforcing your building’s vulnerable features, extend your protection by managing larger defensible space strategies that reduce the intensity of nearby flames and radiant heat exposure.
8. Relocate Structures Further Away from the Building
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- Place all structures like storage sheds, detached covered patios or break areas, commercial pergolas, garbage enclosures, and similar structures at least 30 feet away from the building.
Why? Burning sheds, gazebos, and other structures increase the risk to a building because of the additional radiant heat, flames, and embers produced. Moving these accessory structures farther away better protects the building.
9. Eliminate Back-To-Back Combustible Fencing
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- Within 5 feet of the building, Critical Prep already requires noncombustible fencing.
- In the 5-30 Foot Defensible Space Zone, remove or modify any combustible fences that run parallel (back-to-back) and closer than 5 feet apart.
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- Replace one fence with a noncombustible option as needed, and coordinate with neighbors or property owners if fences are shared.
Why? Back-to-back combustible fences can trap debris between them, creating a susceptible fuel bed for embers to ignite both fences. The two fences together provide greater fuel for a more intense fire.
