Cleaning flagstones and sealing??

[Jon Stones]

Hopefully someone here can help me.
in 10yrs of cleaning and restoring slate/ terracotta/ sandstone/ marble/ granite ect have just been to look at first flagstone floor and boy is it a mess.
whilst it have never been worried about taking on a task of restoring a stone floor and failing this one has me a bit concerned.
first of al floor is grubby (shouldn't be a prob to clean) but what concerned me is that some are crumbling the lime grout has gone in places and cement has been used where corners have been lost.
their appears to be no damp in floor although there is no damp course but their are signs of efforesance in places.
any suggestions appreciated pebs

 

[White Room]

How long has this floor been down....

 

[Jon Stones]

Around a hundred yrs or so

 

[Spud]

Jon you could clean it and then use an antique wax as a finish it was popular back in the day with terracotta floors it will cover over some of the repairs you may need to clean first , then re grout with lime mortar then seal and use the antique wax as a finish , I have also seen brown boot polish used as a finish coat on flag stones and it looked beautiful

 

[Lithofin BOB]

Hi Jon, once floor is cleaned / repaired be aware that any topical finishes ,waxes/ emulsions will/ can trap moisture . This can lead to water staining whitening of the sealer/finish and possible spalling ( bloating of the stone/ delamination) even a breathable impregnator can cause issues pushing moisture to the walls even. If you are wanting to use an impregnator try a water based as this won't bite you ( show application marks) as a solvent one may . Possibly recommend maintain only if there is real moisture issues and let it all breath as it has done for a hundered years

Cheers