Cracked or crumbling mortar joints: what it is, how serious, what it costs

In a brick or stone wall, mortar fills the joints between the bricks; a French report says « joints de mortier ». It is meant to be a little softer than the brick: it wears first, and it can be redone without touching the brick. That job is called repointing, « rejointoiement » in French.

Reports say “cracked joints”, “crumbling” (the mortar breaks up under a finger or a tool), “missing joints” or “repointing needed”.

It depends on how much. A few cracked joints are maintenance and can wait. Crumbling or open joints in several places are more pressing: water gets into the wall, freezes in winter and breaks the brick, and it can damage what is behind.

In analyses, I put them under “Fix first” when they are deteriorated across a good part of a wall, near a balcony, or together with rusted lintels and stair-step cracks.

Redoing a few joints: $300 to $700. Repointing one side of the house: $2,500 to $7,000. Repointing the whole house: $10,000 to $25,000.

The range is wide because everything depends on the area, the height and the scaffolding.

These are ballpark figures for Quebec, to be confirmed with quotes.

1. How many joints are affected, and on which walls?
2. Does the mortar crumble when scraped, or is it only cracked?
3. Are there also broken bricks, stair-step cracks or rusted lintels in the same spot?

Does your report mention mortar joints? Upload it: in five minutes, I tell you what comes first, what to have checked and what to ask the seller.

A mason. Ask which mortar they plan to use: on old brick, mortar that is too hard can damage it, because the brick then wears instead of the joint.

Its cause needs to be found before the joints are redone: a rusted lintel pushing the brick, or foundation movement. A mason, and an engineer if needed, can tell.