Scottish Roofing Slate and Building Stone Quarrying Could Re-Start

RESEARCH HAS FOUND that re-starting Scottish roofing slate and building stone production in Scotland’s quarries could be viable.

It could see products brought back into the market such as West Highland slate, Highland Border slate and Macduff slate.

The research into re-starting the stone markets was for Historic Environment Scotland (HES). The organisation is responsible for looking after 300 historic monuments and buildings in the country. Maintaining these heritage buildings depends on access to materials that mirror those used at the time of construction.

Scottish Roofing Slate

In 18^th and 19^th century Scotland, a vast industry supplied building stone for a range of building, paving and roofing. The industry served markets in Scotland, the UK, and for export.

The industry declined and nowadays only a limited quantity of stone used in Scotland is sourced from Scottish quarries. No roofing slate is quarried commercially in Scotland today although an application for renewed extraction of West Highland Slate at a quarry on the Isle of Luing is currently being considered.

The British Geological Survey (BGS) report suggests how the supply and use of Scottish building stones can be increased, including increasing production at active already quarries. It highlights the building stones and quarries most crucial to maintaining historic buildings and for new builds to help with Scotland’s transition to net zero.

Roofing and Building Stone Market

Researchers found that:

• the cost of imported stone construction materials has risen by up to 98 per cent since 2015, possibly due to increasing fuel prices and shipping costs
• the Scottish and UK construction industry is increasingly vulnerable to erratic pricing and market volatility, due to an over-reliance on imported materials
• increased ranges in stone production locally create a more resilient supply chain and provide assurance of supply
• 139 disused building stone quarries and 31 quarries that currently only supply crushed-stone aggregate may have the potential to supply a significant proportion of Scotland’s building stone needs

Graham Briggs, Materials Project Manager at HES, said: “The dwindling supply of local materials to protect fundamental parts of Scottish history is placing unique pressures on those who wish to maintain and protect our traditional and historic buildings.

“A renewed Scottish building stone market would not only create rural skilled jobs and reduce carbon emissions, but also improve conservation outcomes for our important historic buildings. With that in mind, indigenous stone suppliers are faced with increased pressures and costs that make them uncompetitive against cheaper imported materials.

“The report demonstrates that Scotland is more than capable of being self-sufficient with regard to its building stone requirements going into the future; however, this will require investment and support through innovation in procurement.”

Roofing Slate Imports

The report found:

• over 5 million tonnes of building stone are imported into the UK each year
• roofing slate imports command the highest price – Scotland is particularly vulnerable to this, with no current source of Scottish roofing slate
• the cost of imported stone has almost doubled since 2015

The BGS say reliable figures for the quantities and costs of imported roofing slate are to come by. However, using the latest figures available, the report shows that about 250,000 tonnes of roofing slate were imported into the UK, at a value of c. £125m in 2022 – more than double the value in 2020.

Since 2020, the cost of roofing slate rose from £450 per tonne to £600 per tonne in 2022, a rate that fluctuates considerably within an upward trend.

Slate Supply

Imogen Shaw, Building Stone Scientist, BGS, said: “If Scotland wants to continue to build in its traditional stone, conserving heritage buildings and ensuring new builds are also in keeping with the historic landscape, then action needs to be taken to source more stone locally.

“Our latest report is a vital resource for policymakers and potential investors, providing them with a clear snapshot of current supplies that will help them to identify opportunities for growth and better inform investment in indigenous building stone production.”

Read the report: Development potential for building stone resources in Scotland.

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