Chimney mortar repair done joint by joint in Palm Springs North

Joint conditions that call for repointing

Brick industry maintenance guidance lists the joint conditions that usually call for repointing. We look for each of them on every face of the chimney.

When a face shows these conditions, we mark the area and explain whether the damage is local or spread across the chimney. The pattern also hints at where water is coming from.

• Mortar eroded back from the brick face
• Mortar that crumbles or has voids
• Hairline cracks through the joints
• Cracks where mortar has separated from brick

Filling the deepest joint sections first

Where mortar has failed deep into a joint, the deeper parts are filled before the rest. Federal preservation guidance describes compacting the new mortar into those areas in several layers, bringing them up to the general depth before the joint is finished.

Filling a deep void in one thick pass traps soft mortar behind a hardened skin. That mortar shrinks and can pull away. Working in stages takes longer, and it gives a solid joint from the back to the face. We explain this if your chimney has deep voids.

Firebox joints are a separate job

The joints inside a firebox face direct fire and use refractory mortar made for heat. They are not repaired with the mortar used on the outside of the chimney. That work belongs to firebox repair.

If you mention cracked joints inside the fireplace, we look at them during the inspection and explain what they need. Exterior tuckpointing and firebox work each have their own line on the estimate. You can approve one without the other, and each uses the material its location requires.

Matching color on a partly repointed face

When only part of a chimney face is repointed, the new joints sit right beside old ones. Brick industry guidance says partial repointing should match the existing mortar color, using pigment where needed.

We compare samples against the existing joints wet and dry, and we match to the less weathered mortar in sheltered spots. Where the boundary between new and old would be obvious, we may suggest ending it at a natural break, such as a corner or the roofline.