Hi houzz people! I’m doing some DIY reno and needing advice on what I should do to raise a concrete floor in my laundry. I'll try not to be too confusing... ISSUES

1. The existing floor is lower than the floor coming from the internal hallway.
2. The floor is currently tiled. (In good shape and level)
3. There is no fall or existing floor waste

SITUATION The laundry is in what used to be part of an internal garage so the existing tiled floor is lower than the connecting internal floor (which appears to be vinyl/underlay/floor boards… See attached). The height from the existing floor to the top of the internal floor boards is 30mm then an extra 15mm for underlay and vinyl. 45mm in total. The height I need to raise the floor to will be determined by the thickness of the tile (or timber etc) I use to bring it inline with the current internal floor, but for now lets just I’m raising it 30mm. I’m wanting to raise the floor so that there is no step from the hallway (a trip hazard and unsightly) and also to be able to give the floor a slight fall down to the external door (or waste). I was contemplating putting in a floor waste but I’ve been told I don’t really need one in this situation. I also may not need the fall, but would still like to know the best solution if I should do that. My concern is what would be best to raise the floor with considering the height and if it requires a fall. I want to avoid lifting the existing tiles, I believe I can prep them to take levelling compound which would give me a nice level surface, but if I need a fall then I assume I’d have to use something like ’Deck Mud’?. FLOOR AREA 3.7m x 2.1m (7.77m2) Cabinets/bench will cover 3.7m x 600mm of that area. WHAT I’D LIKE TO KNOW IS… Raising the floor:

1. Can levelling compound be used to raise the floor 30mm? (to match the top of the floor boards.) What are its limits?
2. If I need a fall, can ’Deck Mud’ be used over the existing tiles or would I need to remove them first?
3. I'm assuming the correct fall ratio is 1:100, the distance is 2800mm so the floor thickness would go from 30mm down to 2mm at the lowest... is that correct?
4. If I made it level without a fall, could I just use normal concrete or is 45mm too thin? (Thinking I could just concrete it then polish the concrete)
5. Would you recommend I put in a floor waste?

Flooring:

1. If I don’t have a tile or concrete finish, is it ok to use engineered timber panel flooring in a laundry wet area? ( I have seen wet area versions but not sure about them)
2. If not, could I use any other timber solutions? (I’m wanting to go for either a timber or concrete look rather than tile)

I’ve attached a couple pictures to help explain… excuse my messy sketch and handwriting. Would love any feedback or suggestions! Thank you! :) (FYI the photo with the washing machine to the left is looking from the hallway into the laundry area, the other is looking from the garage into the laundry towards the external door.)