Stonemasonry & Pointing

Traditional stonework and pointing problems in older buildings

Stone has been used for building in Scotland for over 5,000 years and Stirling’s architectural heritage is testimony to its durability. Both whinstone and sandstone are used in Stirling. These have typically been built with mass-masonry wall construction. This means there is no cavity such as that found in modern construction. They rely on the lime mortar used to build and point each stone to transport moisture which has entered the wall to the outside surface where it evaporates.

Most 18th and 19th century stone buildings were designed in a very informed way to control the flow of water over their surface. For example, the cornice and string courses below function to direct water away from the face of the building as well as being decorative.

Masonry checklist

Look out for surface decay on stones
Check for visible gaps between stones
Keep an eye on loss of detail on projecting areas

You can find out more in the HES Inform Guide ‘Masonry Decay’ along with other publications in this series.

Traditional stonework and pointing - common problems

Stone decay

Look for individual stones that have lost so much of their surface to decay that they now appear set back from the surrounding stones.

Loss of detail

Keep an eye out for a loss of moulding detail on the underside of cornices or projecting courses can leave the drip function ineffective allowing water to run down the face of the building.

Open joints

Where the mortar pointing has failed there will be gaps visible between the stones. Daylight can sometimes be seen between sections of projecting cornices and into chimney flues.

Inappropriate materials

Check to see if cement mortars have been used. Modern cement based mortars often appear very grey. They are hard and brittle and usually erode more slowly than the softer surrounding stone leaving the pointing mortar proud of the stone surface.

Salt deposits (efflorescence)

White powdery deposits on masonry surfaces are often the result of soluble salts in water passing through the stone. As the water evaporates at the surface salt crystals are formed and left behind. These deposits can indicate that an area of masonry is subject to continual wetting.

What you can do

Maintain rainwater disposal goods and leadwork on the roof to water from entering the stonework.
Regularly check for missing pointing between stones.
Owners of traditional buildings in Stirling can join the Traditional Buildings Health Check and get a regular drone survey of their roof

If you need work to the masonry of your building, always ensure that you appoint a contractor who is experienced in stonemasonry and the use of lime mortar. Contact the TBHC team for advice.

Stonemasonry & Pointing

Traditional stonework and pointing problems in older buildings

Traditional stonework and pointing - common problems

Stone decay

Loss of detail

Open joints

Inappropriate materials

Salt deposits (efflorescence)

What you can do

Building Care

Rainwater Disposal

Leadwork

Chimneys