Concrete/wall in existing garage man-door. Concrete question

2018-03-12 20:25:09

I have an exterior man-door on my garage I'd like to remove and wall off. The exterior of the garage is cedar siding. Replacing that and framing the doorway in is not the issue. My concern is pouring concrete over the existing floor. There is a foundation on the exterior wall, maybe 8" as the garage is attached to the house

Can I just pour new concrete over the existing concrete without leaking issues? I plan on drilling into the floor and insides of the foundation doorway walls, and adding lengths of rebar to tie it all in. Will this be enough? Thanks