Repairing a Granite Retaining Wall Damaged by Tree Roots and Rebuilt with Lime Mortar

Granite retaining walls can suffer damage over time, especially when tree roots grow beneath or alongside them. This granite wall originally built with cement mortar that was damaged by tree roots and then rebuilt using lime mortar in Bucksburn, Aberdeenshire.

This is an image of the wall after it was rebuilt with lime mortar

Tree roots can exert significant pressure on retaining walls. As roots grow, they expand and push against the wall’s foundation and joints. This pressure can cause cracks, displacement of stones, and mortar deterioration. The original wall in this case was built using cement mortar, which is rigid and less forgiving to movement. Over time, the roots caused the mortar to crack and weakening the wall’s structure. During the dismantling process we discovered the wall had little to no foundations in places. New foundations were poured before the wall was rebuilt.

An image of the wall before work commenced