Lime Mortar vs Cement Mortar
Choosing mortar for old brickwork is not simply a question of which mix is strongest. The existing brick and mortar, building age, exposure and repair objective all matter.
Why lime mortar is often considered for old brickwork
Traditional lime mortars can accommodate movement and allow moisture to migrate through the joint. This can be important where older, softer bricks were designed to work with relatively flexible and permeable mortar.
Why hard cement mortar can be a problem
A very hard cement-rich joint can behave differently from softer historic brickwork. In some situations this can concentrate stresses or change how moisture moves through the wall. The correct repair specification depends on the building rather than a universal rule.
Before repointing
- Inspect the existing mortar and brick condition.
- Identify whether the wall is historic, modern or a later repair.
- Check whether the brick is soft, porous or damaged.
- Match the appearance and joint profile where heritage appearance matters.
- For listed or historic buildings, obtain appropriate professional or conservation advice.
Brick identification matters
Understanding the brick can help inform a repair decision. Our old brick identification guide explains how to photograph and measure historic or reclaimed bricks before choosing replacement materials.
Identify the existing brick