Garage Firewall Attic Access

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.

Garage firewall attic access.

In situations where there is attic access either to the house attic from the garage or to the garage attic through the ceiling difficulties can arise. When installed in a garage ceiling this thin wooden membrane replaces a portion of the fire resistant drywall. 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. The access cover on a folding ladder is usually a mere piece of inch plywood.

The door is required to be self closing. R302 6 dwelling garage fire separation. 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. The wall between a house and garage must be separated by 1 2 drywall.

In such case the attached garage firewall house separation wall should extend all the way to the roof decking or garage section should have a 5 8 drywall ceiling installed. 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. Each of these materials is combustible so having a wooden access cover separating an attic and garage compromises the fire separation.