How to ensure floor is level between two rooms?

[Joeyree]

We are renovating our very old house and it has timber floorboards in the main house and the extension is concrete flooring.

We will be installing carpets in lounge, family room and bedrooms and vinyl sheeting in the kitchen, dining, bathroom, laundry and entry.

The kitchen has floorboards and we will need to install an underlay (masonite/ply) to level the floor for the vinyl sheeting.

Our problem is the kitchen floorboards join onto the extension with the concrete flooring ( flooring is currently flush between rooms) which will also be laid with vinyl sheeting. 

This will create a lip between the 2 rooms. 

Should we also lay masonite/ply on the concrete floor aswell to keep flooring level?

Is masonite or ply better?

If ply what size?

We  also need to choose 1 that will do the wet areas aswell in the bathroom/laundry. 

We are not interested in restoring timber floors, laying tiles or planks.

Thankyou

[MitchellMc]

Welcome to the Bunnings Workshop community @Joeyree. It's wonderful to have you join us, and many thanks for your question about installing vinyl flooring.

You could also lay masonite sheeting over the concrete. However, a transition strip can be placed across the doorway to hide the difference in height.

Masonite would be the recommend underlay for dry areas and cement sheeting for wet areas. Here's the installation guide for our vinyl sheet flooring.

Please let me know if you have any questions.

Mitchell