Hi There

[Gazzer]

Without knowing what methods and products were used inc what was on the wall before tiling it is hard to say.
The yellowing of grout in such a short amount of time could be down to background contamination, grouting too soon before adhesive has dried. It could be something as simple as using a sponge which has been used for some other colour grouting. Maybe it was polished off with a cloth and the colour has run from the cloth. It could be bad grout or even if the walls were cleaned down with some form of cleaning agent or bleach.

Its very cheeky of him to expect you to scrape the grout out though.
have you scraped the surface of one joint to see if the yellow is all through the grout or just on the surface ?

 

[dot59]

It's just on the surface. It seems to be worse at the top!

 

[Gazzer]

Unfortunately without seeing it , it will be hard to say but no way is it smoking so soon.

 

[Gazzer]

Hi Kilty, I used a damp cloth to clean the tiles a couple of days after they were put up. There was a slight discolour at that point. He said the grout he used had tiny holes in it and therefore the nicotine discoloured the grout. I smoke in the kitchen and have had tiles in there for 6 years and they are no where as discoloured as those in the bathroom

Why has grout got tiny holes in it ??