Tough Job ahead

[CanadianRuss]

I had a demo today. The is is a washroom at a car dealership. All the grout is dark. After cleaning the grout is all dark except this one little area. I tried venom renew on the edges but had no luck. The rest I used esteam alkaline tile and grout cleaner with a citrusolve booster. Any suggestions. Some other issues were some areas came right up nice after agitating others that weren't even in traffic areas are still dark.

 

[Mikey P]

Color seal those areas.

Alk and acid clean first

In six weeks it will look like you were never there anyways.

 

[Old Coastie]

It looks as if someone else already did that. Too, in a carwash area they are raining slops from soil, salt, brake dust and oils, all of which penetrate the grout.