tiling over existing tiles fixed to sand/cement screeded brick wall

[dominator99]

Hi all

This is my 1st posting & would appreciate member's feedback

I tiled my power showered wet room 10 years ago with 150x150x6 contract whites in a diamond pattern, floor to ceiling with, I believe, waterproof premixed tub adhesive.
The floor was tiled with 150x150x10 floor tiles over the original (over 30 years old) DPM'd concrete floor
All 4 walls were originally internal garage brickwork which I skimmed with a cement/sand screed before tiling.
All original wall tiles (approx 15 m2) seem sound (no hollows when tapping).
The power shower consists of an overhead shower head & 4 horizontal body jets fed by a 1.5 bar H/C pump

The other half wants new 600x300x4.5 floor/wall porcelain tiles to replace the existing wall & floor tiles (15 m2 wall & 3 m2 floor).

My questions are:

1. Would tiling over the existing wall tiles be recommended & if so, what existing tile preparation & adhesive would be recommended?

2. If removing the exsting tiles is the best option, would removal of the existing cement/sand screed back to the original brickwork also be recommended?
If this is the case, again, what adhesive would be recommended?

3. What grout would be recommended (I used a 2-pack white grout in the past on my bathroom but it was horrible stuff to work with; like spreading chewing gum!)
I suspect grouts have evolved since I last used 2-pack approx 10 years ago

4. I planned to cover the existing floor tiles with the same 600x300x4.5 unglazed porcelain tiles.
Again, what adhesive & grout would be recommended?
Would sealing the new floor tiles be recommended to protect aginst staining?
I've also heard that using black adhesive or grout can cause colour bleeding into the tiles over time causing a colour change in the tiles appearance - I noticed this effect with my original black floor tiles that took on a brownish hue after
a period of time having used both black adhesive & grout & would apprecaite advice on whether this is still an issue today.

Sorry to witter on but I'd rather take the advice of professional tilers than risk getting it wrong (penny wise & pound foolish springs to mind!)

 

[White Room]

Re: tiling over existing tiles fixed to sand/cement screeded brick wal

Hi and welcome...firstly I would remove existing tiles, waterproof tubbed gear dos'nt ring any tunes with me and the render if done correctly should be solid depending on the mix and sand used.