Burnaby Stone Care in Salford, Manchester, are best known for their stone cleaning, but since being bought by Elton Tudor at the end of 2006 they have increased their repertoire and their geographical coverage.

Few subjects relating to stone and conservation arouse as much debate as stone cleaning. Tomes have been written about it and conferences held to discuss it. But Elton Tudor believes that whatever system is used, the success of cleaning in the end comes down to the skill of the person carrying out the work.

Elton is the Managing Director and owner of Burnaby Stone Care in Salford on the western outskirts of Manchester. He has 15 years of hands-on experience of cleaning stone. And what that experience has taught him is that every project is different. It takes a skilled eye to know precisely what to use to clean stone and, importantly, when to stop cleaning it.

The sandstones of the northern part of Britain where Burnaby have traditionally carried out most of their work have raised the most controversy about cleaning, especially in Scotland. In Glasgow in particular there are some truly appalling examples of inappropriate cleaning of the sandstone. The uniformity of rows of terrace houses and apartment blocks has been ruined by indiscriminate cleaning using chemicals that have changed the colour of the stones and left facades streaked and patchy.

Elsewhere, excessively aggressive gritblasting has removed the faces of some buildings and even the faces of some statues, removing detail and leaving the stone vulnerable to accelerated decay.

In the light of some of the work that has been carried out it is not surprising there has been so much controversy about what is the best way to clean stone and even whether it should be cleaned at all.

But as far as Elton Tudor is concerned that is the wrong debate. The question that should be asked is not how cleaning should be carried out but who should do it.

Choose the right company with management and operatives who understand what they are doing and you will get the required results… as long as you allow them to be involved in the decisions about how to achieve those results. And because the operatives carrying out the work are so instrumental in achieving the required result, Burnaby do not subcontract out cleaning.

A job Burnaby have just finished working on is not stone but Canadian Cedar – in other words, wood. It is the 9.75m long totem pole at Manchester Liners, carved and painted in Canada by Douglas Cranmer of the Kwakiutl tribe of British Columbia in 1969 and transported to Manchester for the chairman of Liners. It is a significant artefact and an important part of the cultural heritage of the area – so important the British Museum were consulted about its restoration.

After 30 years hidden away outside an industrial unit in Salford, the totem pole is now being restored to stand tall at the new Media City development on Salford Quays. It is being re-painted by Kevin Cranmer, a nephew of the original carver. But before he could get to work, the old paint had to be removed and the wood of the totem pole cleaned up in preparation.

Burnaby, who were established in the same year as the totem pole was carved and carry the red maple leaf of Canada on their logo (although they are not a Canadian company) were called in.

Burnaby often use the Jos / Torc cleaning system from Stonehealth that is specified by many conservators for stone cleaning but have also developed a super-low pressure abrasive cleaning system of their own. They like to demonstrate how gentle it is by removing the print from newspaper pages without damaging the paper.

It works at a pressure of 7psi (about half a bar). The type of abrasive used and the grit size depends on what is being cleaned and how aggressive the clean needs to be.

Normally, the larger the size of grit used the more aggressive the cleaning. As the totem pole is wood, a gentle clean was needed. However, a larger size grit had to be used so it did not embed itself in the grain of the wood.

So to ensure it was only the paint and dirt that was removed and not the wood, the abrasive used was a mixture of flurok from copper smelting and glass, producing a hardness of five on the Mohs scale. That might be considered fairly aggressive, but because it was only being delivered at 7psi it did the job relatively quickly (it took three days) yet without damaging the wood of the totem pole.

Another job Burnaby have been working on lately is cleaning paint off the sandstone and render of Affleck’s Palace, a shopping centre in Manchester that describes itself as “a totem of indie commerce in Manchester’s Northern Quarter”.

Again, a machine Burnaby have developed themselves, a low-pressure wet abrasive system, was used, although it is not as low pressure as the one used for the totem pole or they would have been there until Christmas.

On the borders of Scotland at Fowberry they used the Doff superheated water system from Stonehealth to clean a large stone house, and they have just finished using the same system to clean the sandstone of the Princess Hotel in Manchester, a Victorian building that was formerly a cotton warehouse. There, they also used a pH neutral detergent that they mix themselves.

Elton says it does not clean as well as acidic or caustic cleaners, which he maintains will not damage the stone as long as they are used properly and washed off thoroughly, although he concedes that some cleaning companies do not use them properly, which has led to the sort of problems that now deter people from using them at all in Scotland. There are also environmental issues when using aggressive chemicals and in any case, the preference these days tends to be to produce a less extensive clean so that the building continues to show the patina of age.

These are some of the projects that have been keeping the 11 people employed by Burnaby busy. Nevertheless, like the rest of the industry, Burnaby are not as busy as they were before the recession, so they have decided to combat the downturn by expanding their horizons.

They have always carried out the occasional stone repair work associated with cleaning, but last year they completed their first major restoration project at the Grade II listed Compton House, now a Marks & Spencer store in Liverpool, which was built in 1865 as the world’s first department store – five years before Bon Marche opened in Paris. (The project was featured in this magazine in December.)

In the 1970s the sandstone cornice, dentil moulds and carved adornments to impressive oriel windows at either end were hacked off to make way for granite cladding and a plastic shopfront sign. Last year Burnaby restored the original features using Peakmoor stone from Block Stone worked by masons B D Brookes in Yorkshire and with carvings by John Hargreaves. They also cleaned the facade and replaced unsympathetic hard cement repairs that had been made over the years with indents and lime mortars.

Burnaby are also looking for more work outside their traditional stronghold in the North West. Again, they have always been willing to go further afield and have worked as far south as Chatham Dockyard for architects Purcell Miller Tritton, who knew Burnaby through their Liverpool office. But they have tended to get enough work to keep them busy in the North West. When they have gone further afield it is more usually north, including some projects in Scotland.

Now, though, they are looking south again and have carried out tests on buildings in Covent Garden, London, for a project there. They have acted as consultants but hope it will develop into a cleaning and repair contract for them.

“We do a fair bit of consultancy work,” says Elton. “In Manchester we have a good relationship with conservation officers. They come to us because they know we have no axe to grind about any particular system or product for cleaning. We just suggest the best way of doing the job and generally they go along with our recommendation – they can’t be experts at everything and we have more expertise than they have about cleaning and restoration.”

Elton’s eminently practical knowledge of stone cleaning comes from 15 years in the industry, more than 10 of them working with Tony Bannister, an accepted authority on the subject and respected member of Stone Federation, who founded Burnaby Stone Care in 1969.

And in case you are wondering why the company is called Burnaby and the logo incorporates a maple leaf, it is because Tony borrowed some money from his sister to set up the business and his sister was living in Burnaby in Canada at the time.

Elton started on the tools and moved into estimating before buying the company when Tony retired at the end of 2006.