Fire Separation Walls

During a home inspection we review components and elements that make up a fire separation firewallwall. In terms of the home, fire separation walls are built to prevent or delay the spread of fire and/or fumes between separate units. Fire separation walls are found between units in condos, townhouses and apartments, but are more commonly seen as the separation wall between an attached garage and the home. The purpose of this article is to provide general information about fire separation walls and why they are important in terms of safety.

For more information I recommend contacting your local building department for specific specifications and code requirements.
When inspecting the fire separation wall between a house and garage we are checking for the following elements:


  • Doors should be less than 1-3/8” thick and should be an approved solid-core or honeycomb-core door, preferably an identifiable fire rated door (see local codes).
  • Any service door leading directly into a bedroom is not permitted.
  • Doors between the garage and the house should have tight, undamaged seals to prevent seepage of fumes into the house.
  • Doors between the house and garage should contain self-closing hinges to ensure doors cannot be left open.
  • Any windows in the doors should be fire-resistant.
  • No pet doors should be installed in doors between the house and garage.

Walls & Ceilings

  • A fire separation wall between a garage and house should be covered with drywall (gypsum board) and should be taped and sealed to keep fumes from entering the home. Further, a fire separation wall should extend from the floor in the garage up to the roof, separating attic spaces between the house and garage.
  • If there is living space above the garage, then the garage ceiling must be covered with drywall (gypsum board) and should be taped and sealed to keep fumes from entering the home.
  • All wall and ceiling penetrations should be sealed with a fire rated caulking to ensure that fumes cannot seep into the home. Further, caulking should be applied around door trim, electrical penetrations, etc.
  • Duct work running through the garage to access any portion of a home must meet a certain thickness requirement (see your local codes) and should have no openings in the garage. Further, ducts should be sealed to keep fumes from accessing the rest of the home.


  • Floor should curb up at the fire separation wall to ensure that spilled liquids cannot seep under the wall and into the home.
  • Floor should be clear of any flammable materials.

We recommend and encourage clients to bring their fire separation walls up to these standards. Many of these items can be tackled in a weekend project by a “do-it-yourselfer” with proper instructions. Please contact us with any questions that you might have about fire separation walls, we will do our best to answer your questions or provide you with the information or personnel you need!

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