Chimney Repointing in New Jersey

What repointing is

Mortar joints are the part of a brick chimney that wears out first. Repointing means removing the deteriorated mortar to a sound depth and filling the joints with new mortar. Done right, it restores the chimney's strength and its ability to shed water.

You may hear it called tuckpointing. The terms are often used interchangeably, though tuckpointing strictly refers to a finishing style with a contrasting line.

Signs your chimney needs repointing

• Mortar that is recessed, crumbling or sandy
• Gaps you can see or feel between bricks
• Loose or shifting bricks
• Brick faces flaking or breaking off nearby
• White powdery deposits on the brick
• Water stains in the house near the chimney

Why mortar fails

Mortar is softer than brick on purpose, so it takes the wear. Rain, freezing and thawing, and sun break it down over decades. A chimney stands tall above the roof with all four sides exposed, so it weathers faster than a wall.

Matching the mortar matters

New mortar should be no harder than the brick around it. Very hard mortar on softer, older brick can force moisture and stress through the brick instead of the joint, and the brick faces start to flake. On older chimneys we pay attention to the mortar mix and to matching the look of the existing joints.

What the work involves

• Removing the failed mortar by grinding or raking, to a sound depth
• Cleaning out dust and debris
• Dampening the joints so the new mortar bonds
• Filling and tooling the joints to match
• Replacing any broken or spalled bricks as needed
• Cleaning the brick face when finished

Smearing mortar or caulk over failed joints is not repointing. The old mortar has to come out for the new mortar to hold.