28/04/2026
TS3: Repointing Masonry
One of the most common issues we see during inspections is mortar that has eroded, cracked, or recessed back from the face of the brickwork.
It’s easy to assume this means the wall is failing — but in most cases, the brickwork itself is still perfectly capable of doing its job.
A lot of repointing failures come from using a mortar that’s simply too strong for the original construction. When the new mortar is harder than the brick, it can cause the brick edges to spall or break away. Strong mixes also tend to shrink as they cure, leaving fine cracks that let water straight back in.
On the other hand, mixes that are too weak — or not protected from frost while they harden — can crumble or detach. Getting the balance right is essential.
The preparation is just as important as the mix. Joints need to be raked out to a consistent depth (usually around twice the width of the joint), cleaned thoroughly, and repointed in small enough areas that the mortar can be compacted properly.
The finish matters too. An ironed or “bucket‑handle” profile is the most durable because it compresses the mortar and sheds water effectively.
Repointing has the ability to restore weather protection and is a good way of preventing further deterioration. But if the mortar is soft all the way through the joint, the wall is distorted, or there are signs of movement or corrosion, that’s when a structural assessment becomes important.
