Garage

Fire hazard – Garages

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The garage is often overlooked when assessing wildfire vulnerabilities, despite being one of the most hazardous parts of the house. Generally, garages are not well sealed since they are not heated or cooled. Additionally, garages often have multiple vents, especially if they are equipped with water heaters or laundry appliances. As most household flammable materials are stored in the garage, embers entering through gaps or vents are extremely dangerous. Moreover, garage doors often have windows in the top sections that can easily be broken by heat or flying debris (although the glass in newer doors is tempered). In the window section, you can find more information about fire resistance of glass.

Any type of garage without doors, such as an attached carport, is an even greater concern. Typically, garages of this type have a large amount of combustibles and plenty of nooks and crannies for embers to lodge.

How can you protect your garage?

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  • In garages with roll-up doors, the top and bottom can be weatherstripped (the bottom is often already sealed to prevent water entry). The roll-up mechanism should be adjusted for a good seal. Similar solutions apply to tilt-type doors.
  • When the doors are closed, any gaps at their tops, sides, and bottoms can serve as entry points for embers, potentially igniting some of the combustible materials inside. Due to the importance of embers, plugging these gaps will greatly improve your garage door's ability to resist wildfires.
  • Car-entry garage doors with glass panels can either have the panels replaced with fire-rated glass or simply filled in.
  • For attached carports, as a first step, combustible materials should be minimized. This still poses the greatest hazard to your home, so proper garage enclosure should be given serious consideration.
  • Entry doors with single pane windows can have their windows replaced with fire-rated solutions or with panels.

California regulations

Vehicle access doors (garage doors) are covered under Chapter 7A. Since they are considered exterior doors, they must comply with the exterior door provisions. These options include:

  • Being made of non-combustible or ignition resistant material
  • Having a 20-minute fire resistance rating
  • Comply via SFM 12-7A-1 for walls
  • Comply prescriptively by being constructed of solid wood meeting minimum thickness requirements for stiles and rails [1-3/8 inches] and field panels [1-1/4 inches].

Products and assemblies that have complied with Chapter 7A can be found in the WUI Product Handbook. Since “ignition resistant” and “non-combustible” are performance-based characteristics (i.e., there is a standard test to show compliance), these materials are included in the Handbook.

Examples of garages

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Garage door with bottom gap. This roll-up garage door has not been properly adjusted, creating a gap at the bottom where embers could easily enter. Make sure that the garage door is properly programmed or that the rails are adjusted to ensure full closure.
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Garage door with top gap. This roll-up door has a gap at the top that cannot be filled with weatherstrip, exposing the garage to embers. Materials that cover the gap through the edges can be added. In this example, a 2x4 piece has been tacked on to show how the upper opening in the framing could be blocked if it were extended the full width.
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Garage door with glass. This garage car door has glass panels that could break during wildfire exposure. Flames could then spread along the door and the eave. Tempered glass would behave better than annealed glass, but could still break during a fire. The glass could be replaced by panels.
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Garage door with vents. Gaps between the garage door and framing, as well as the vents at the base of this door, would be vulnerable to the entry of burning embers. Replace the vents with fire-resistant ones (see Vents section).
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Garage space without door. Attached spaces without a door are extremely vulnerable to embers. In this case, large amounts of combustible materials are accumulated in the garage and they should be removed. Alternatively, a door could be installed to prevent embers from entering the space.
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Entry door with tempered glass window. The window in this particular door is tempered glass, but is also single pane which does not offer a great protection in case of fire. Replace the single pane window with a double pane (if possible), or consider replacing the window with a panel.
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Steel-clad entry door. This door provides both fire resistance and security from break-ins.