At first glance, it is just the sort of business you might expect tucked away in a small valley just south of Witney. But while Cardinal Cast Slates produces authentic looking Cotswold-style roof tiles, they are actually manufactured on site by founder Richard Parsons.

The history of the firm dates back to when Mr Parsons, who was in the building trade at the time, needed stone roof tiles for one of the barns at Claywell Farm, Ducklington, which has been his home since the early 1980s.

He said: “I didn’t like the products that were available at the time, so I thought I’d have a go at making my own. The most important criterion was to replicate the varied and compound shape of stone slates.”

Not having any prior experience with slate manufacture, Mr Parsons, 61, approached the process with a fresh eye.

After a great deal of experimentation, he arrived at a method where rows of up to 100 double-sided vinyl moulds are held vertically in large clamps while tinted concrete is poured into the hole at the top.

There are many characteristics of Cotswold stone tiles that only the Cardinal Cast Slates method can reproduce. By hanging the moulds vertically, rather than flat like other manufacturers, all Cardinal’s tiles have contours on both sides.

The double-sided nature of the moulds allows the tiles to be tapered at the sides to give the characteristic thin edge.

Each tile thickens authentically toward the top and then forms the folded over ‘nib’, which hooks over a batten on a roof. The nib has a hole to allow the tile to be nailed to a batten, which is traditionally done every fifth course.

Once developed, the method was put under patent protection and Mr Parsons was joined in the business by partner John Beresford, also 61.

“It’s actually the process of clamping the mould together then pouring the concrete through the hole in the top of the nib that is patented,” Mr Parsons explained.

Once filled, the racks of moulds are agitated to ensure good distribution of concrete throughout each mould. The racks are then left to set and quality is inherent at this point too, as Mr Parsons explained.

“If concrete dries too fast it falls apart, like a biscuit. We discovered that our racks were insulating the tiles so that they set properly, whatever the time of year.

“It was always in my mind to sell the product as soon as I knew I could come up with something that I was happy with.

“The breakthrough was finding the right product for the moulds, a vinyl that is very rubber-like in its properties.”

This vinyl can be used again and again, so after a mould has served its time of about a year, it can be melted down and re-cast.

As well as being environmentally friendly, this inherently economic method allows Cardinal to supply more than 150 different slate shapes and sizes, which also adds to the authentic look of the product.”

To prove the point, Mr Parsons points out the roof of an outbuilding, now the site office. This still has its original stone tiled roof but one of Cardinal’s tiles has been slipped in as well. It is impossible to tell which one without Mr Parsons’ expert guidance.

A major contributor to the recent stability and growth of the company has been the workforce, which now includes a number of Polish craftsmen.

He said: “They are very organised and almost manage themselves. If they hit a problem, they either fix it, or work around it.”

Another contributing factor is Mr Parsons’ dogged determination to continually improve the manufacturing process.

In many companies people are often tempted to leave well alone, but Mr Parsons is always chipping away at the bottlenecks to make production easier and faster for staff, without affecting quality.

“One simple example was filling the mixers with 10 tonnes of material, which used to take one man four to five hours of shovelling every other day. Now that filling is all done by conveyor belt,” Mr Parsons said.

The next innovation is a control mechanism, so the filling can be done automatically from two mixers, with two slightly different pigmented mixes.

Previously, Mr Parsons would have to make slates to customer orders, with consequent long delivery times. Now small orders can be guaranteed from stock.

Mr Parsons said “This also now gives us the ability to supply larger developments, and I am pleased to say that we have never failed to fulfil a customer order.”

Name: Cardinal Cast Slates Established: 1992 Owner: Richard Parsons Number of staff: Ten Annual turnover: Confidential Contact: 01993 778557 Web: www.cardinalslates.co.uk