concrete porch footers

hello, i am constructing a 4ft by 10ft porch on the front of my home. it does not support a roof. it will have two steps off the front to the sidewalk. do i need a footer? Or do i need to dig 36in (32in frost line)? the city building says i do not need a permit or anything and that digging down that deep is not necessary because it is not supporting a roof. I have already dug 24in is this enough? some say if i do not dig 36in frost will get under and lift and lower and the porch will sink or crack. please help need to pour by wed.

thank you for all your help in advance.
amys girl friday

 

You need to dig down below the frost line or you could indeed have frost heave. You don't really need a footer. Just use round form tubes for posts at each corner of the deck.

 

thank you for your information.

 

A footing at the bottom is much better to prevent frost heave: Building a deck: expert advice from ... - Google Books
Gravel as backfill will not freeze as most soil will: How Aggregates Prevent Frost Heave SULIS - Sustainable Urban Landscape Information Series: U of MN.
Added assurance against frost jacking: ESB: Frost-Protected Shallow Foundations

Be safe, G