Regards, Peter

First of all Using an alkline cleaner undiluted is not actually always going to help, many, if not most, actually NEED water for them to work, so ironically NOT diluting them does not make them stronger or more potent.

Also, I suspect from your description that the dirt is ‘builders’ dirt – i.e cement based and most likely grout residue/haze. If it is an alkalie will do little in any case.

You cannot use an acid cleaner though as that will damage the stone for sure.

I would agree with you that the next step should be a microabrasive like Microscrub. – use this with a little water and if you can get one (hire) a mono brush machine – rotating machine, slow rpm (175 to 350) with either natrual fibre pads or medium brush head.

If this does not work, you have to up the abraive a little bit – but now you will be removing stone, only microns but still removing stone, where as with the Microscrub you will not be.

So, next try a honeing powder – for this you most definately need a machine and a wet vac again yoiu can hire them. This proicess is a little more involved so I suggest you email me if you ned further infomration

Hope this helps
Ian

We recently had a limestone floor put in our kitchen. Our builders (it was part of a house renovation job) were incompetent and did not take care with the tiles. As a result they are very dirty and require deep cleaning.

So far I have tried applying an undiluted alkaline solution agitating it with a sanding machine. But this seems to have little or no effect.

As a next step I had thought to repeat this process but with ‘microscrub’ (EU version of nanoscrub.

I am a bit concerned about doing too much as the tiles are only half an inch thick and I am concerned I might scrub myself through them!

What advice would you give?

If it isn’t possible to clean the tiles is it possible to bleach them? At the moment they have unbecoming rust coloured patches on them.

Cheers

Pete