Attached Garage Fire Containment

At Home Safety, Fire Safety


Download Attached Garage Fire Containment

<- Go Back

Fires that begin in attached garages are more likely to spread to living areas than fires that originate in detached garages. For this reason, combined with the increased risk of severe fire due to the multitude of flammable materials commonly found in garages, attached garages should be adequately sealed from living areas. A properly sealed attached garage will ideally restrict the potential spread of fire long enough to allow the occupants time to escape the home or building.  
Attached Garage Fire Containment

Why are garages fire hazards?

  • Oil or gasoline can drip from vehicles which can collect unnoticed and eventually ignite.
  • Flammable liquids such as gasoline, oil and paint are commonly stored in garages. Fluids containing solvents, such as paint thinners, are flammable in their fluid form and may create explosive vapors.
  • Heaters and boilers, which are frequently installed in garages, create sparks that can ignite fumes or fluids. Car batteries will also spark under certain conditions.
  • Mechanical or electrical building projects are often undertaken in the garage. Fires can easily start if a careless occupant is welding or cutting near flammable materials.
  • Vehicle fires caused by faulty extension cords are a common problem. Never plug in the block heater cord if your vehicle is parked in a garage. Be sure to check all cords for fraying, cracking or signs of damage and replace immediately if problems are found.


  • The entry into the house from the garage must have a 20‐minute-rated fire door and be equipped with a self‐closing mechanism. Self-closing doors are much safer than doors that can be left ajar.
  • If doors have windows, the glass should be fire‐rated.
  • Doors should have tight seals around their joints to prevent seepage of fumes into the living areas of the house. Carbon monoxide, with the same approximate density as air (and often warmer than surrounding air), will easily rise above the base of an elevated door and leak through unsealed joints.
  • Pet doors should not be installed in fire‐rated doors as they will compromise the integrity of the fire barrier.
  • It’s beneficial to have at least one step leading up to the door from the garage. Gasoline fumes and other explosive gases are heavier than air and they will accumulate at ground level. Their entry beneath a door will be slowed by an elevation increase.

Walls & Ceilings

  • Garages should have 5/8” fireguard drywall installed on the wall that separates the house from the garage. For the best fire protection, we recommend all garage walls and the ceiling be lined with drywall, especially if the garage, house and attic are connected.
  • Two layers of 5/8” fireguard drywall are required on the ceiling of an attached garage if there is living space above the garage.
  • All drywall joints shall be taped or sealed.
  • In garages that have access to the attic, a hatch cover made from an approved, fire‐rated material should protect this access at all times.
  • A heat detector that is hard‐wired or wirelessly interconnected with the smoke alarms inside the house is strongly recommended and is required by code for newer homes.

Fire Prevention Measures in Attached Garages

A number of measures can be used to properly seal, separate and protect your living space from a garage fire. Be sure to check with your local building official to confirm the building code requirements if you are building or renovating your attached garage.