What the previous guy did

[Dumbo]

I Was tiling a floor in a house whilst a plumber was ripping out a bathroom and he was coming out with 3 layers of tiles . Wondered why that window didn't let in much light .

 

[Qwerty]

And this is the reason I don't tile on tile...... 2 layers of tiles and blown render which didn't sound hollow apart from a small area at the bottom. Only one way to deal with it was to rip it all off, dry line and then tile. A small very basic job for an old dear, but there was no way I was going to take any chances.