These could have been laid many years before and it is unlikely that they were ever treated with sealer. Therefore the historic rugged flagstone floor that you inherited when you bought your dream country home may need a little work to restore it to its best.
The majority of traditional flagstone floors across the UK are generally Antique Yorkstone. This is a sandstone which historically came from Yorkshire or Derbyshire. However in certain parts of the country it is possible to find Antique Pennant Flagstones, Antique Blue Lias, Antique Purbeck Flagstones or even Antique Cotswold Flagstones
The first step is to seek a tiler who is used to dealing with historic flagstone floors. Restoring an old floor is not necessarily difficult but it is always best to use a stone fixer who has experience over someone starting from scratch
The process would start with putting a chemical on the floor to break down any sealer, wax and the inevitable layers of dirt. Once this is done the floor will need to be washed with water to remove any grime on the surface. Once the floor is clean it will then need to be sealed. Different brands of sealer contain different amounts of colour enhancer and therefore the end user has some flexibility over how strong they want the finished colour to be. The final stage would be to wax the floor to give it the patina of a true flagstone floor.