How stone is used to restore buildings

Natural stone has been an intrinsic part of building history for centuries. No other material offers so many benefits in terms of its beauty and versatility, which is why we continue to conserve and restore our beautiful old buildings with building stone.

Not only does natural stone look stunning, but it has high thermal capacity, it’s durable, sustainable, green and it has great design flexibility. And that’s why it is such a popular choice to build with today, and has been for centuries.

Lincolnshire Quarries

Here at Stamford Stone, we own two prestigious Lincolnshire Quarries, Clipsham Bidwells and Clipsham Medwells, which sit on the county’s famous Oolitic belt and from which some of the most renowned limestone is quarried. Since 2018, we became the exclusive global supplier of Clipsham limestone which is used for building and restorations projects all over the world.

Colour tone

Many restoration projects throughout England rely on Clipsham limestone because of its beautiful creamy, gold tones. Planners and architects frequently specify its use in place of the renown Bath stone.

Some blocks of Clipsham golden cream limestone are blue-marbled inside – described as ‘blue hearted’. Whilst this is avoided by some architects, others such as Donovan Purcell purposefully used the blue marbling to create replacement columns in the Galilee Porch of Ely Cathedral.

Historical uses of Clipsham limestone

Clipsham limestone was used to create parts of the Great North Road in Roman times and it is also believed to be the source of the famous London Stone landmark. Medieval builders used Clipsham limestone in the construction of Windsor Castle in the 1300s. What’s more, about 50% of the limestone above the plinth of Big Ben has been replaced with Clipsham limestone. Other prestigious buildings restored with Clipsham limestone include the Palace of Westminster, Windsor Castle, the Nazrin Shah Centre in Oxford and a variety of Cambridge Colleges.

Importance of repairing historical stone

Despite being classed as ‘durable’ stone is porous and can suffer over time from wear from water absorption. Weathering erodes stone too – the natural acidity of rainwater, airborne pollutants, plant growth and dirt accumulation can all cause damage. Stone can be scratched and cracks may form, weakening its structure.

Repair techniques

There’s a whole variety of repair techniques that can be employed to replace or reinstate aged stone. Some typical repair techniques include:

• Repointing – removing and replacing failed mortar.
• Reanchoring – introducing a fixed point of contact.
• Pinning – securing non-corrosive rods through the stone into the masonry backing.
• Patching – small colour-matched material applied until the area mirrors the original profile.
• Sculpting – re-carving eroded stone.
• Resetting – returning stone to its original position.
• Crack repair – injecting adhesive material into cracks to avoid further water damage.
• Consolidation – filling voids within the stone.

State-of-the-art restoration

At Stamford Stone, we have invested in the latest 3D Point Cloud software and training for our highly skilled stone experts so they can scan existing buildings in minute detail and reconstruct any intricate designs.

“You can count on us for expert advice and guidance. Whether you’re looking for architectural stone specialists for a restoration project, or for designs and plans to be drawn, you will find our vast knowledge and experience of working with architectural masonry invaluable,” explains Graham Sykes, Design Manager, Stamford Stone.

“First of all, we don’t just own the limestone quarries and supply the stone. Our love of stone runs much deeper than that. We’ve grown and nurtured a team of experts who can support you in every aspect of designing, building and renovating with natural stone,” he adds.

Maintenance and cleaning

In order to preserve stone surfaces and to prevent future deterioration, it is essential to provide ongoing maintenance including:

• Routine inspections – to detect early signs of stone damage and joint failure.
• Regular washing – to avoid the accumulation of dirt and pollutants.

It’s important to always make sure you correctly identify stone before cleaning as certain cleaning agents and treatments, if improperly applied, may actually accelerate the physical deterioration in the stone.

Water washing is usually the best treatment. However, you may need to use a purification system to eliminate the corrosive effects of any impurities in the water.

You can read more about our favourite conservation and restoration projects. Alternatively, if you have any questions about our stone you can view our FAQs or contact us on 01780 740970.