When I scrape the rubber adhesive off, there’s still a trace amount left and so I wonder whether the next course of adhesive might not adhere properly. Is this valid…

Thanks Chippy! That’s good to know. Is it something that you come across fairly often?

I all. New here. I want to replace the tiles in my en-suite and pulling off the 225x150mm ceramic wall tiles has revealed a black adhesive that’s somewhere between foamy…