Does anyone have experience with adding frost protected shallow footings under an existing slab? Existing garage is 24×22. Need frost footings in order to attach to the house.
Reason for this method- very narrow lot so extensive excavation would be very difficult.
To narrow of a lot to move the garage and pour footings and blocks.
I live in east central MN so regular frost footings would need to be 48″ deep.
The local building official isn’t very well versed in Frost-protected shallow footings so I’m trying to gather as much information as possible.
I would have to agree that the local official in not well versed in shallow frost protected foundations, as they are not allowed under a garage in Minnesota per the building code.
Section R403.3 of the 2015 Minnesota state building code: . . . . . Foundations protected from frost in accordance with figure R403.3(1) and table R403.1(1) shall not be used for unheated spaces such as porches, utility rooms, garages and carports, and shall not be attached to basements or crawl spaces that are not maintained at a mean temperature of 64 degrees Fahrenheit.