The term “York Flagstones” is used almost generically nowadays to describe most random stone flags, and I have even seen the term used in an eBay description for a batch of used imported Indian stone.
 
Wherever you are in the country, you will find a local variant of flagstone. Here in Warwickshire, we have hotspots of Blue (and white) Lias flags, the blue and brown Hornton ironstones, and toward the Cotswolds, yellow limestone. And yet, throughout the County, the inevitable “York” flag. Our county town streets are paved with them, and they are the favoured flooring for many of our public houses and Coaching-Inns. I have personally seen most of them at close quarters within my research.
 
When buying reclaimed, bear in mind that a garden flag may have originally been laid by Victorians, having been quarried, split and sawn, but prior to this process was actually 300 million years in the making.
 
A recent overhaul of an 18th century rainwater culvert local to me revealed York stone of massive proportion used to bridge the culvert. Between 5 and 9 inches thick, the smallest was seven foot long, and many examples were 10ft by 12ft! These were Rossendale stone (that’s Lancashire, not Yorkshire!) yet any dealer asked to buy would not argue the toss. York it is, then.
 
Essentially, for the buyer, we are looking for grey or brown. Within the greys we will include the Lancs flags, but from there on in it is about grades. Riven, or smooth? Anyone propping a beer mat under a table leg will guess which is which. The term “Cathedral grade” is bandied about far too much in the trade, so I’ll try to explain my own definition of a Cathedral-grade. A smooth, undulating face “pillowed” at the edges and as clean as a Coronation Street doorstep.
 
Not necessarily from a cathedral, as there are not many cathedrals up for demolition or refurb (though not impossible!) but definitely Internal, and most likely domestic use. As rare as hen’s teeth, as they say. Worn by footfall and housemaids’ knee maintenance over a century or two, a true “Cathedral” flag is the crème de la crème. But let’s not get too purist.
 
We have the “red-tops”, probably the most prized among the Architectural Salvage Trade. Street flag. Not only naturally worn by footfall, but over time, also blessed by the sun as the ores within the stone are exposed by wear, and react to the sunlight to produce a deep-red bloom. Plus chewing-gum.
 
We haven’t talked about thickness! Which brings us onto Mill flags. The term is not used too openly in trade descriptions, more likely used when the dealer asks “It’s not mill flag, is it?”
 
A general guide to flagstone prices might be that thick is cheap, thin is dear. Not quite. The Mill flag demonstrates that we also have to consider whether the flags are suitable for reuse, for Mill flags can be fabulous or fraught with problems. The Industrial Revolution brought our dark satanic mills, and York Stone became the choice of flooring on every floor, sometimes six floors high. Impervious to clogs, and the endless rumble of cast-iron wheeled baskets and skips. Not impervious to oil, and machines need oil.
 
Not all floors contained machinery, but we have to consider the use of the building once the mills were redundant: the buildings since have been segmented into workshops ranging from typical sewing-machine sweat-shops to car body repairs. I cannot tar them all with the same brush…
 
…for Mill flags can be fabulous. Beware those advertised as “pressure-washed” or “sand-blasted”. It is likely they have everything from hydraulic oil, suds, or worse in them, which will only be apparent once exposed to sunlight or central heating. An oil-slick in your kitchen or round the pool, the only remedy will be to rip it up and start again.
 
If you are to bring this wonderful flooring into your life, I am not going to tell you the secrets of how to identify the pitfalls. I will point you in the direction of your local Architectural Salvage Dealer. It is their job to undertake this quality control on your behalf, based on their experience.
 
There is no reason why garden flag cannot be brought indoors, or mill-flags given their new lease of life in the open air like a retiring pit-pony. Riven by nature, a garden flag is typically greened with moss/algae and slippery when wet. This can be pressure-washed off without losing patina.
 
Remember that cheaper (5” + thick) can be fantastic but are labour-intensive. Even the smallest of these flags could raise an involuntary fart from the strongest of blokes and the larger examples can extract the same effect from a forklift.
 
And don’t forget the transport costs! Compare 6 square metres per pallet (5”thick) with 14 square metres (2” thick) in terms of weight and bed space on a wagon, and there is a considerable difference in cost per metre, but forget any thoughts of off-loading either batch by hand. Cheap can turn out very expensive, but if you are aware can be very rewarding with a stunning end result.
 
Ask the provenance! Where did they come from? It always pleased me to tell visitors to my barn conversion that the hall flags were from the Gents Toilet in Solihull. Oh, yes. We pressure-washed, alright. It was a batch that, in a previous life, I had also seen at close quarters.
 
As a dealer, I’m always on the lookout for quality in York Flagstones. Quality will always sell, especially as these items get rarer by the day. Price? Inevitably rising, year on year. I cannot avoid the classic nutmeg, that once installed and laid faithfully well, the quality will be enjoyed long after the price is forgotten.
 
Most recently, rising fuel prices and transport running costs contribute greatly to the retail price. They don’t get off-site and cross-country by themselves. Hence, your first port of call is the reclamation yard most local to your project. Salvo!