Utilising cement mortar in a historic building that was originally pointed with lime can be incredibly destructive to its structural integrity. The construction of historic buildings often uses soft brick or stone that is prone to a certain amount of movement. This movement will cause the weakest portion of walls, most commonly masonry with Portland cement mortar, to crack and separate.  By employing lime-based mortar in historic buildings, we are not only upholding the traditional technology but also affording a repair material that is compatible with softer building materials such as porous masonry bricks and stones.  The soft and porous properties of lime mortar ensure that it becomes the weaker element in the structure allowing for less damage overall. Essentially lime mortar serves as a defensive barrier for substrates, safeguarding them from deterioration due to external agents such as frost and salt. The abundance of long-lasting monuments built using this very same material serves as clear evidence that hydraulic lime mortar is an incredibly resilient product.