I want to pour a concrete patio slab where as the concrete will be nearly level with exterior doors. I just don't know what I need to do about the interface with the concrete to my home. My home is vinyl sided with one and a half courses of vinyl below the exterior doors. Do I remove the vinyl below the doors at that elevation where concrete will be meeting building and use tar paper/flashing/felt on the sheathing? Will I need a footer at this interface, too? Yes, this is a frost area where the home is and typical footers are three feet deep. This will be a rather large patio, twenty by fourty feet or so.

We want to be able to walk out our doors and not have to step down. Any thoughts or advice appreciated.