Garage and dwelling separation

Separation wallTable R302.6#

The wall between an attached garage and the dwelling must be finished with at least 1/2-inch gypsum board or equivalent on the garage side. Walls that also support floor or ceiling assemblies above habitable space require 5/8-inch Type X gypsum board on the garage side.

Separation ceiling#

If habitable space is located above the garage, the ceiling of the garage must be finished with at least 5/8-inch Type X gypsum board and the supporting structure for the habitable space above must also be protected.

If the garage has habitable space above only part of it, the protected area extends to the full line of the supporting structure, not just directly beneath the habitable room.

Door between garage and dwellingR302.5.1#

Doors from an attached garage directly into the dwelling must be one of the following:

• Solid wood, at least 1-3/8 inches thick
• Solid or honeycomb core steel, at least 1-3/8 inches thick
• 20-minute fire-rated door

Door location restrictionsR302.5.1#

Doors from a garage cannot open directly into a sleeping room. They must open into a hall, living space, or utility room first.

Garage floorR309.1#

The garage floor must be concrete or other approved non-combustible material and must slope toward the main vehicle door or a drain to prevent liquid fuel from flowing into the dwelling.

Common inspection flags#

Most frequent garage separation failures:

• Wall gypsum missing at the top plate where it meets the roof sheathing
• Ceiling not upgraded to 5/8-inch Type X where habitable space is above
• Hollow-core door installed between garage and dwelling
• Door from garage opening directly into a sleeping room
• Penetrations through the separation wall not firestopped
• Garage floor sloping away from the overhead door toward the dwelling