Serpentine floor tile spalling

[Old Mod]

It sounds like it's just the grout powder that got sealed over??

Yeah sure sounds like it could be, DO NOT use any acid based product, it WILL degrade the stone.
Check the literature again and see what it suggests to clean it.
I would firstly remove any heavy residue with the blade.
If it can be cleaned in the conventional manner of using an alkali, pour neat strong bleach on the blemish and cover with a clear piece of plastic sheet. Leave for 24hrs, it will act as a poultice.
Obviously best case scenario would be to try it on a scrap or inconspicuous area first.
Don’t be impatient, let it do it’s stuff.
Then rinse with fresh water.
This will remove any sealant.
Wait a good 7 days before applying any more sealant.
Then seal periodically when staining becomes ore difficult to remove.
Good luck.

 

[Deleted member 52962]

Thank you so much for your help
Hopefully this is the cause.

 

[Old Mod]

Thank you so much for your help
Hopefully this is the cause.

It’s no problem at all @beemo thats why we’re here.
Just keep us updated, that’s all the thanks we need. 😊

 

[Deleted member 52962]

Will do, thanks again

 

[Deleted member 52962]

Just wanted to give an update.
The next day after we thought we had success the crusting was back.
We finally got in touch with the quarry and they said it was Efflorescense from the water used during the install, and it can be removed with steel wool, and that it will continue to crust until all the moisture is out, and to keep going at it with the steel wool until it stops.
Once it's all out we can polish the area to bring back the shine.
What a pain in the butt, well at least it doesn't sound too bad and the tiles can be saved, if only we knew this from the start. Well live and learn

 

[Old Mod]

That’s great news, an easy fix really.
Pleased for you. 😊