What bonded screeds on Hardy Ceramic Tile underlay?

[TryingMyBest]

I am trying to retrofit an open-plan bathroom into an old timber floor house. I need to create falls but want to minimise screed thicknesses. Can I bond Australian Builder's Tile and Paver Screed to Hardy Ceramic Tile underlay to create a "bonded screed"? What method or product would I use?

Can I add in either a Dunlop or Bastion waterproof membrane in between the Hardy Ceramic Tile underlay and the screed, and still achieve the same level of bond?

[EricL]

Hello @TryingMyBest 

Welcome to the Bunnings Workshop community. It's sensational to have you join us, and thanks for sharing your question about bonding tiles to screed and tile underlay.

I'm currently unaware of a screed that doubles as a tile adhesive. I know that screed needs to cure for several days before you tile over it, otherwise the trapped moisture will simply pop the tile off. If I recall correctly the waterproofing membrane is the last layer to go on top of both the tile underlay and the screed. Perhaps you can tell us more about the conditions of your bathroom project and we can provide recommendations in regards to screed, tile and adhesive installation. 

Let me call on our experienced members @Nailbag, @Dave-1 and @AlanM52 for their recommendations.

If you have any other questions we can help with, please let us know.   

Eric

[Nailbag]

Hi @TryingMyBest 

There are no shortcuts when it comes to bathrooms. Here are the layers:

1. Floor base timber or concrete slab

2. Tile underlay if on timber floor

3. Screed for walk-in shower base

4. Waterproofing membrane

5. Tile adhesive

6. Tiles

Nailbag

[Dave-1]

Good Morning @TryingMyBest 

I havnt had a lot of experience in screed or tiling I must admit. The steps that @EricL and the list that @Nailbag has specified are the ones that keep things in line, "There are not shortcuts when it comes to bathrooms" That @Nailbag has siad is perfect Anytime I hear of someone thinking of a workaround I imediantly think of the issues it raises. And I am one of the people who has  and keeps on having ideas for workarounds for my bathroom It may seem easier but nope, stick to that list and it works best.

Dave