Sandstone and limestone have been widely used throughout the United Kingdom for centuries and the soft stones are readily shaped and carved into beautiful profiles and designs.

That's the positive side of the soft stones. The downside is that these stones are frequently victim to our harsh weather. Wind, rain, leaking gutters and more recently winter road salts all take their toll.

The most commonly displayed damage includes erosion and delamination. The use of inflexible portland cement based mortars invariably causes stone to flake, spall and crack.

These are problems we see everyday as a stone restoration specialist. With competent skills you can use this stone repair mortar to undertake these kind of stone masonry repairs.

We only use St Astier Lithomex, a specially formulated Natural Hydraulic Lime and aggregates based mortar.  Coloured to match the colours of traditional Scottish buildings, it is the ideal product for the repair or simulation of stone, masonry and even brick.

Only natural breathable repair products should be used.

Never use stone repair products that are predominantly based on:

• epoxies
• polymers
• resins
• cement
• other synthetic materials

The simple reason to avoid these artificial products is that whilst they may provide a pleasant façade, they they create a non-breathing finish and trap moisture and salts within the stone. A nicely finished surface may hide severe and continuing disintegration behind the scenes. In some situations this has actually led to the collapse of stone columns in medieval buildings.

Stone 'sealer' products may be very useful at protecting interior surfaces, such as granite, marble and travertine from staining, it should also be avoided on the exterior of buildings. While it might be applied to masonry wall as a method of preventing water penetration, it will cause far more problems by not allowing trapped moisture to evaporate.

Click here to view the SPAB statement on water repellents and their effect on historic buildings

Cement based repairs invariably fail and separate from the stone, eventually falling away from the underlying stone.

Well intentioned, but misguided repairs can cause extensive damage to stone.

Repairs frequently include:

• Ashlar wall stones
• window cills
• lintels
• cornice
• copings
• plinths.

For sympathetic and authentic restoration, Lithomex can be shaped to recreate detailed profiles.

Call us:

0777 614 9787    -   01698 826 941