English victory on the slate in siege of Stirling

Published on Saturday 23 May 2009 18:59

IT IS one of the iconic symbols of Scotland. For centuries Stirling Castle has stood proud above the Forth, its mighty walls hewn from the same stone on which it stands. The landmark, however, may no longer be as truly Scottish as it appears.

Restorers, Scotland on Sunday can today reveal, have been forced to put English slate on the roof of the castle's iconic Great Hall as the nation runs out of the material that defines most of its historic buildings.

The news comes amid growing concerns among architects and heritage experts that many of Scotland's landmarks – and hundreds of thousands of homes – could lose their distinct look as stocks of the Scottish slate run short.

Historic Scotland, the government agency which owns and runs Stirling Castle and much of the rest of the nation's built heritage, is desperate to see slate quarries, closed for half a century, reopened to supply the stone needed.

But many experts are now resigned to seeing thin, brittle foreign slates replace the traditional thick, multi-coloured and "randomly" cut Scottish variety.

"We tried our best to find something that would match the Aberfoyle slate that would have been on Stirling Castle," said David Mitchell, of Historic Scotland. "The nearest we could find was from England. Up to now our policy has been to try to reclaim, recycle old slates, salvage them from one old building for another. But we are rapidly getting to the stage that this is not possible."

Historic Scotland has some stocks of the stone. But supplies are running out – and much of the rock that is left, despite its longevity (the best Scottish slate, like that from the former quarries at Ballachulish, has a lifespan of up to 150 years), is no longer fit to be used.

Although the roofs at Stirling Castle are periodically replaced, the fact that slate from a mine in Cumbria has been used since 2002 was not known until now. Although the type of stone is similar to that found in Scotland, it often has a greener colour to it.

Geologists have found huge reserves of usable slate ready to be mined in Scotland, both in the west and the north-east. But no commercial operator has come forward with a viable plan to dig it out.

"The feeling is the government has done as much as it can and it is now up to the private sector to try," Mitchell said. "The big slate importers are of the view that they can solve the problem, that they can match Scottish slate.

"The imported slate is now much better than it ever was. Some of the stuff coming into the country in the 80s and 90s was shockingly bad. Ideally, however, we would like to see quarries reopen here."

Some slaters are predicting a crisis. Graeme Millar runs a family slating business in Peebles and does a lot of work in Edinburgh. "We believe there are up to 10,000 homes in the world heritage sites needing reslating in the next five years alone. This is a huge issue. We simply don't have the Scotch slate we need to do the job.

"Edinburgh – and other towns and cities – could end up looking very different indeed if we put imported slate on their roofs."

Millar wants to see the quarries open as soon as possible. He said: "We know the slate is there. We know that the quality is good. We know we need it. Now we have to get it out of the ground; we can't afford not to."

The castle isn't the only building in Stirling that needs new slate. The Scottish Stone Liaison Group, a body bringing together experts in the field, earlier this year calculated that the old town below the ramparts needed hundreds of tons of Scotch slate every year.

The group's chief executive, Colin Tennant, said: "We have to accept that in the short-term we are going to lose some of our distinctive slate roofs.

"But in the long-term we must find a source of Scottish slate if we are going to keep the look that fits with our architecture and our sense of place." Tennant would eventually like to see rules that would mean only Scottish slate could be used on Scottish listed buildings. He draws hope from the revival of slate mining in England and Wales, whose quarries may provide skills now lost north of the border.

Foreign firms, meanwhile, are salivating at the prospect of reroofing Scotland. There are half a million homes in the country built before 1919, many with ageing slate roofs. One firm, Cupa of north-west Spain, the maker of one in four slates in the world, already has Scotland in its sights.