Laying vinyl over a floor with both particle board and tiles

Question

In our laundry, I need to replace a section of the floor due to water damage. I am planning on putting a yellow-tongue 19mm thick particle board over the left-hand side of the photo to fix the floor. The right-hand side has tiles (area is about about 900mm wide).

Over the whole room, I want to put a vinyl floor or similar. I am worried about the unevenness of the tiles coming through the vinyl and being able to feel it underfoot. What are my options for making a smooth base (my guesses below):

1. Nail 6mm plywood sheets across the floor. This is straightforward on the wood, but how to attach it to the tiles?
2. A self-levelling compound. Does this just go over the whole floor, tiles and wood? Do I then need to waterproof it?

Answer 1

I would remove the tile. Then put down the sub floor as you described (not sure about your choice of material) over the left hand section. If what you then have is fairly flat, cover the entire floor with 1/8" luan plywood (I think this is what they used in my laundry). The final covering was vinyl plank.