Hot Dog: When The Backyard Grill Attacks!
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Grilling outdoor during warmer months is a great way to bring people together, so long as users remember they are literally playing with fire.
Spring weather is wonderful in the south. It’s been a year since I moved and got rid of most of the things we never used in the garage. Now I’m perseverating over which grill to buy so my fiancé and I can finally make grilled turkey legs and stir-fry vegetables while watching the neighbor kids play tag between houses. Despite my pale bald head that sunburns almost instantly, I feel the need for some fresh evening air. Very little makes the afternoon better than sitting in a metal chair and joking about the neighbor’s gazebo plans while you casually take food off the grill.
I have to be honest – I sort of fear the back yard. There are gnats, neighbors with all manner of projectiles (frisbees, basketballs, volleyballs and even footballs have flown past me when all the neighborhood kids are running around!), and all the dust that my edger kicks up. But the social energy of such an active development is why I moved there. It seems a waste to eat dinner on nights like these. After all, a backyard barbecue is the highlight of summer.
But managing fire is one of the most dangerous things you can do in flip-flops. As a Mechanical Engineer and CFEI (Certified Fire and Explosion Investigator), I know a grill’s ease of use can make us forget that we are playing with fire right outside our most valuable possession – our home.
Damage from grills can happen fast, and it can be radiant, convective or even conductive. The National Fire Protection Association (NFPA) reported in May 2025 that:
“between 2019-2023, gas grills were involved in an average of 9,287 home fires per year. This includes over 4,600 structure fires…”
Considering 80% of US homeowners owned grills in 2023 – up from 64% in 2019 before the global pandemic – Americans largely use their outdoor cooking spaces with no major issues. Even considering the 21,000 emergency room visits for grill-related injuries annually, these self-contained outdoor fires perform their duties without incident the vast majority of the time. As a society we have improved safety by requiring safe distances from siding and flammables, and with warning and education.
Hot exhaust from grills can melt vinyl siding, char wood siding and crack mortar. The IFC requires a minimum of 10 ft. spacing from walls. The IFC, Section 308.1.4 provides guidance on spacing from walls and siding. Image credit: Bartlett Fire District
The IFC (International Fire Code Section 308.1.4) represents a minimum requirement of 10 ft. from any combustible construction for grills. The IFC also prohibits grill use on combustible balconies or decks outside of one-family or two-family dwellings. While inconvenient for the most dedicated outdoor chefs, the code addition is responsible for a reduction in injuries in the past 11 years since it was adopted.
Most grill users want to be safe. We clean our grills after each use to mitigate grease fires (which are cited in 1 in 5 incidents), distance grills from vinyl or wood siding, and keep yard games away from active grills. Responsible propane users also inspect their connections, using soap frequently to prevent explosion hazards. However, exhaust can come in contact with obstacles and grillers don’t always realize the danger. Vinyl siding warps or melts at temperatures as low as 160°F – 165°F. Solid wood siding can ignite at 500°F – and long term exposure to elevated temperatures has resulted in ignition temperatures of solid wood as low as 250°F. Animals or even other humans can knock over grills. Freestanding systems can quickly spread fire to the surrounding area.
Fire damage from gas grills to siding will typically be indicated by v- or u-shaped damage originating around grill height. Charcoal grills can create embers that light fire at greater distances. Propane (the most common outdoor grill fuel) can develop line or connection leakage. Since propane is heavier than air, standing cooks may not smell the leak until the gas fills a large enough area to create an explosion.
The NFPA reported in 2020 that 46% of fires originated from some sort of fuel leak or mechanical failure of the grill. These leaks can be due to corrosion, bending, and even manufacturer defects in hose lines, crimps or connections. The origin of the fire is of particular interest in forensic work, where the manufacturer’s design can affect the likelihood of fire development.
NFPA (National Fire Protection Association) 54/ANSI Z223.1 (the National Fuel Gas Code) and IRC (International Residential Code) Chapter 24.2 contain propane delivery and piping codes for above and below ground piping, as well as the following items of special interest in outdoor grilling:
- Pressure Regulators: Must be installed to reduce tank pressure to the appliance’s required inches of water column (typically 11″ WC for propane).
- Shut-off Valves: An accessible manual shut-off valve must be installed upstream of the grill connection, usually within 6 feet of the appliance.
- Point of Discharge: Propane cylinder relief valves must be at least 3 feet away from any building opening (windows/doors) that is below the level of the discharge, and at least 5 feet from any source of ignition or air intake.
Our expert Mechanical Engineers at The Warren Group address manufacturing defects related to grills, as well as fire cause and origin on a daily basis. If you need to identify possible issues with an incident grill, we can help determine the failure mode, as well as identifying any design defects in the product. Either way, enjoy the grilling weather. And don’t forget to grab some onions and peppers on the way home!
Senior Consulting Engineer Brian Tenace, PE, FMCP®, holds a Bachelor of Science in Mechanical Engineering and Master of Science in Mechanical Engineering from the University of Florida, a Fenestration Master through the Fenestration and Glazing Industry Alliance, and is a Licensed Professional Engineer. He has over 15 years of manufacturing and machine design experience in production and quality-driven environments. Over his engineering career, Brian worked in fenestration design in addition to designing hardware, above/below ground spill containment vessels, extrusions, dies and molds. He conducted root cause analyses for fatigue, weld, and corrosion failures in steel, springs, pressure vents and sheet metals. He developed tests according to standards and custom specifications as needed, along with modifying manufacturing processes. His failure analysis experience includes impact testing, design for ballistic protection, water infiltration resistance and corrosion. Brian has an in-depth knowledge of many standards with emphasis on fenestration standards and impact standards. Brian regularly investigates property damage claims involving machinery and equipment in a variety of environments, as well as personal injury, wrongful death, and product liability claims for both insurance adjusters and attorneys.
