Garage Firewall Attic Access

R302 6 dwelling garage fire separation.

Garage firewall attic access.

When installed in a garage ceiling this thin wooden membrane replaces a portion of the fire resistant drywall. There is a high incidence of fires started in garages due to the gasoline and other flammable materials often stored there and either way the intent is create a 1 2 drywall barrier between the garage and house for fire protection. The door is required to be self closing. Buildings with combustible ceiling or roof construction shall have an attic access opening to attic areas that have a vertical height of 30 inches 762 mm or greater over an area of not less than 30 square feet 2 8 m 2 the vertical height shall be measured from the top of the ceiling framing members to the underside of the roof framing members.

This also applies to structural members and this extends to the attic in a common sense type of way. A common defect i that run across sometimes even in newer homes is when there is attic space above the garage and the access cover from the garage consists only of a piece of particle board osb or plywood. The wall between a house and garage must be separated by 1 2 drywall. If there is no ceiling and the roof structure is exposed in the garage then the wall separating the garage from the dwelling must extend up to the underside of the roof sheathing.

Typical garage attic access at least in the majority of chicago land homes including new construction is a square drywall section usually set on four pieces of trim. Each of these materials is combustible so having a wooden access cover separating an attic and garage compromises the fire separation. The garage needs to be separated from the house.