What do you say about a garage converted to a living space and there is no footing where the garage door used to be? Presumably there is a header there and the new wall doesn’t support a load. However, the code says there shall be a footing at “all exterior walls”.
R403.1 General. All exterior walls shall be supported on continuous
solid or fully grouted masonry or concrete footings,
crushed stone footings, wood foundations, or other approved
structural systems which shall be of sufficient design to accommodate
all loads according to Section R301 and to transmit the
resulting loads to the soil within the limitations as determined
from the character of the soil. Footings shall be supported on
undisturbed natural soils or engineered fill. Concrete footing
shall be designed and constructed in accordance with the provisions
of Section R403 or in accordance with ACI 332."
There is a footing under the posts at the end of the header. The framing beneath is not structural so I wouldn’t be concerned about it. Technically the structural wall is still supported by those footings. I like George’s take.
And those footings carry the loads on the sides of the house, just like the footings under the posts at each end of the garage header. The small amount of framing used to close in that opening would be insignificant compared to the weight of one or two vehicles parked on or near that portion of the slab.
The side walls, doors, windows, interior cabinetry, sometimes the gable framing, an attached deck or cover, the basement foundation walls. Probably a few others.
But for the sake of discussion, let’s assume all of that left and right side load above grade is transferred to the front and back and has no bearing(HA!) on the footing. Wouldn’t the same be true of the front gable wall of a garage?
Not sure I get what you’re trying to say. Around here, the garage entry door rarely has a footing. Just a 6" slab all the way across the door opening. No rebar in either the house or garage slab around here. No plastic vapor barrier beneath the garage.
I would say the code writers already addressed the structural support of the garage door wall when they required the header and footings beneath both ends of the header.
Again, the load change from a vehicle door and periodic vehicle traffic to a static 7x16 framed wall is not significant and may even be less. I would be astounded if this were taken to an AHJ and he demanded new footings be poured. But I do think he might need to be the final say.
Joe, do you really think that a non-bearing frame wall weighs any more than a car rolling over the threshold? Even with a floating slab for the garage, the front edge will most likely be at least a thickened edge with (1) #5. The garage floors in my area are mostly integral to the entire monolithic slab on grade with continuous footings.