Solid Hardwood, Engineered and Laminate Flooring - Match Different Floor Heights

I am getting ready to install an engineered flooring system in two adjoining rooms. One room has a slab with no covering and the other room has Vinyl Asbestos tile. Since the tile has the asbestos issues, I was going to leave it down. How can I raise the height of the room with the slab to have one continuous run of planks through both rooms?

Can I use a thicker underlayment in the room with the slab? Should I lay down 1/8" tile or sheet vinyl over the slab? Any thoughts would be greatly appreciated.

Thanks!

I couldn't sleep and was browsing and found this unanswered question. Hope this isn't too late. The height difference shouldn't be an issue. You could feather it out with Ardex Feather Finish if it makes you more comfortable. Don't use thicker underlayment. It'll allow the new floor to flex too much and come apart. The only purpose for the pad is noise reduction. It's called pad, but padding for feel is not why it's used.

Smokey,

Thanks for the reply. After a little further investigation and removal of old carpet of the slab, I have uncovered larger issues.

The entire house was built on a slab. The house had a slab at an elevation of 101'. The house also had a slab carport that was below grade at 100.7'. A some point they enclosed the carport and added 4" to the below grade slab to bring it up to the rest of the house slab elevation. Problem is, they actually made it about 1.5 inches higer than the existing house slab.

What are my options for bringing the "carport" slab back down to grade? Grinding, hammering, etc?

Thanks for any ideas!

Matt