Tiling on existing wall tiles?

[Doug99]

My bathroom wall tiles are sound and level, is it reasonable to retile the bathroom without removing the old?

Cheers

 

[L95]

Depends on the substrate. If it's plaster then it will generally hold around 20kg/M2 or 32kg/M2 if plasterboard. What tiles do you intend to fix over the top? Are the existing tiles already on top of tiles?

 

[Doug99]

The house is only 25yrs old so only the one layer of tiles. The existing tiles are 150x220 and am fitting 450x350.

 

[L95]

Are they porcelain? Either way, 450x350 will require powder as opposed to dispersion (tubbed) adhesive. I would honestly say you might be better off ripping down the old to replace with the new incase the weight causes them to pop off. If it's plaster underneath then definitely.

 

[vinn]

As above, its most always best practice to remove old tiles.
Its a necessity over plasterboard.
And you could be tiling in difficulties over fixtures eg behind bath taps and window reveals & sometimes at rad fixings.