Stone Work Repointing

The methods for repointing brick and stone walls are very similar.

 

There are basically four stages.

Stage 1

Raking out and removal of the old or inappropriate mortar to a minimum depth of 25 mm or until sound mortar is reached.  The exposed joints are then thorohghly cleaned with water to remove all dust.

​

Stage 2

The joint is then moistened to ensure water from the mortar is not drawn into the surrounding masonry causing the pointing to dry out too fast.  For pure lime work mortar joints should not be filled more than 15mm at a time and the joints allowed to firm up before the next application. Once complete the joint and stonework should be moistened again as above.

​

Stage 3

Now the pointing commences  with care taken to avoid the creation of a hard outer surface by overworking the pointing and drawing lime water to the face. After initial set the pointing should be finished of by scraping/brushing to achieve desired appearance and remove residual laitence.

​

Stage 4

Protection of the joint and monitoring during the early stages are important and remoistening by spray after 24 hours and re-working the joint to remove any hairline cracks.  After the initial set the mortar is scraped or brushed back and then washed using low pressure water (care needs to be taken that water is directed out of the joint) in order to rinse the brush marks and remove the debris and expose the aggregate, creating a naturally weathered appearance.  On most historic buildings a brush finish is appropriate. On some buildings there may be a different historic style such as tuck pointing is used to create a more regular appearance. Specific historic styles of pointing should be followed where encountered.