Hardened grout removal - Tile Advice

[H573]

I’ve been asked to clean up a bodged grout job.
The floor is large approximately 135m2 so the customer doesn’t want it all raking out and regrouting( in some places I’ll have to) what’s the best way to clean hardened grout of tiles ( see a few example pictures of what I’m dealing with generally)

 

[Dumbo]

Try an acid based product but test it in an inconspicuous area first , to be honest looking at the picture looks like grout cracked next to tiles indicating loose tiles .

 

[WetSaw]

Looks old too. As above, acid based cleaner.

 

[H573]

Try an acid based product but test it in an inconspicuous area first , to be honest looking at the picture looks like grout cracked next to tiles indicating loose tiles .

Cheers Jcr, much appreciated. Just seen the job today, it’s a right mess. Thought so re the loose tiles. There’s hollow sounding tiles everywhere too.
[automerge]1563376968[/automerge]

Looks old too. As above, acid based cleaner.

Thanks Pdc, I’ll see if I can find one here.

 

[WetSaw]

I'd leave it well alone, I can just see it.... "All the tiles are coming up since you cleaned the grout"

 

[H573]

I'd leave it well alone, I can just see it.... "All the tiles are coming up since you cleaned the grout"

Think you could be right mate, more hassle than it’s worth

 

[Just Rizzle]

id walk from that night mare it will not be worth it more hassle than its worth its a pigs ear and you cant put lipstick on a pig believe me

 

[H573]

id walk from that night mare it will not be worth it more hassle than its worth its a pigs ear and you cant put lipstick on a pig believe me

Cheers Ray.

 

[Memoria damnata]

old grout from the influx. Easy to remove by angle grinder. put a disk for cutting metal. need a vacuum cleaner.