We want to expand our kitchen out over an existing patio concrete slab. Approximately 7ft by 14ft.

To bring the area level to the house, we will need to pour the new concrete 2 inches deep. How should we prep the area?

Our plan is to lay a moisture barrier on top of the new slab and glue hardwood onto that, as we have done in other areas of our home.

Any tips? Advice?
Thanks for the help!

Is your existing home on a slab also or does it have a foundation? Are you in an area governed by building codes and will a permit be needed?

Thanks.

The existing house is on concrete slab as well. Yes, we will need to get a permit.

I guess the first question to get answered is if your slab is thick enough to function as a slab for a living space and how is it attached to the rest of the house. You don't want you addition to flex and move differently than the rest of the home. You might consider covering the old patio with sleeper 2x4 on their side, screwed and glued to the concrete. This gives you space for some insulation and a nailing surface for your new flooring material.

Thanks. Those are great tips. The patio slab is approx 4 inches thick.

I have been told that we could achieve the same stability by screwing and gluing 2x4's to the existing house slab, applying an epoxy layer over the existing slab and pouring concrete over?

The flooring material we are using inside the house is a glue on hardwood, so nailing it in is not necessary. Isulation might be nice, however we do live in Southern California so it's not as much of an issue here.

Thank you for your time on this.

I think that if you do all this (" have been told that we could achieve the same stability by screwing and gluing 2x4's to the existing house slab, applying an epoxy layer over the existing slab and pouring concrete over?
") you will not be near matching your existing home slab. Insulation isn't a big deal in your area but a vapor barrier may be a good call. Your hardwood, is it glued to itself or to the floor or both?