Hidden Risks Lurking in the Garage

Since 1902, the year the first garage was built to house a single automobile (the word derives from the French word garer, meaning shelter), the garage has evolved into a place to do woodworking, make art and music, fix cars and motorcycles, and launch brand-name technology companies. This multipurpose structure poses a surprising array of hidden fire and other dangers.

Early in my insurance career, I’ll never forget a particular claim I reviewed involving a teenager who was working late at night on his motorcycle in the family’s attached garage. The young man was using a metal grinder to flatten a fender when a spark flew from the grinder and ignited some fine steel wool on his workbench. Within seconds, the workbench caught fire and the garage was engulfed in flames.

Regrettably, the young man panicked and rushed into the house to call his father, leaving the garage door open. The fire migrated to the house, resulting in a total loss of the home. Like many people, he had no idea that fine steel wool was extremely flammable.

That’s just one of many eye-opening fire and explosion risks lurking in the garage.

Risks hiding in plain sight

Cordless power tools and cordless electric lawnmowers powered by a rechargeable lithium ion battery are convenient but come with potential fire risk. If they are damaged from improper use, storage, or charging such as dropping, crushing, puncturing, this may cause lithium batteries to fail, presenting a fire and/or explosion hazard during the charging cycle. Additionally, not all chargers automatically shut off when the battery is fully charged. In such cases, the battery can overheat and explode. Storing a rechargeable battery in a non-airconditioned garage in a locale subject to temperatures above 130°F can cause it to overheat, producing the same dangerous outcome. 

Older gas-fueled water heaters not installed on a platform in a garage are another hidden risk. Heavier-than-air gas vapors may gather at the bottom of the heater, where they can come in contact with the pilot light flame and ignite.

Older kerosene-based and electric space heaters without a thermal tip switch pose a different fire hazard. The switch shuts off fuel supply to the burner assembly, if the heater tips over. Without the switch, an explosion or fire is possible.

Many garages also are repositories of oil-soaked rags, paint thinner, oil-based paints, charcoal fluid, motor fuels and other highly flammable products that can spontaneously combust, when stored improperly.

Fire safety tips for your garage

These various threats must be understood and managed before they result in significant health and home risks. Here’s a few helpful pointers:

  • Immediately dispose of oily rags in a container with a tight-fitting lid or in a resealable plastic bag if nothing else is available.
  • If you plan to use the rags another day, fill the container or bag with water to prevent the oils from oxidizing and heating up.
  • Contact the local garbage disposal company to learn the rules on disposing flammable and hazardous materials.
  • Properly store flammable and hazardous materials like oil paint, thinner and gasoline in a metal cabinet.
  • Sweep up wood shavings or other flammable debris for immediate disposal. 
  • Set a timer that coincides with the charging time limit for a rechargeable battery and then disconnect the charger.
  • Hire a home inspector to check the security status of kerosene-based electric heaters and gas-fueled heaters. 
  • And store steel wool in a container until use.

When it comes to the many hidden risks lurking in our multipurpose garages, knowledge of the fire and explosion threat can go a long way to reducing these prospects.


Glenn Tompkins is a senior risk consultant, certified level 1 thermographer and catastrophe management wildfire specialist.

The opinions and positions expressed are the authors’ own and not those of Chubb. The information and/ or data provided herein is for informational purposes only and is not a substitute for professional advice. Insurance coverage is subject to the language of the policies as issued.