Brick repointing for Jersey City rowhouse facades and chimneys

Brick sheds a fair amount of water on its own. The joints are the weak link. On a 19th-century rowhouse around Hamilton Park or Van Vorst Park, the original mortar was a soft lime mix, and after a century of rain, freeze-thaw and salt air, much of it has washed back from the face of the wall. Once a joint is recessed or cracked, a nor'easter drives rain straight into the wall core. A solid brick wall has no cavity to drain that water, so it keeps moving inward until it reaches plaster, wood lintels or joist pockets.

Inside, that looks like a band of blistered paint under a window, a brown stain where the ceiling meets the front wall, or a closet that smells damp after every storm. Owners often suspect the roof first, and sometimes the roof is part of it. A top-floor stain that follows the line of the facade rather than sitting in the middle of the ceiling usually points to the wall. We probe the joints with a pick and take moisture readings on the inside face before anyone opens plaster, so you're not paying to chase the wrong leak.

The brick on most downtown rowhouses was fired softer than modern brick, and it was laid in lime mortar on purpose. The mortar is meant to be the sacrificial part of the wall: softer and more porous than the brick, so moisture and seasonal movement work through the joint instead of through the brick face. When someone repoints that wall with a hard, cement-rich mix, the order flips. The joint stays rigid, trapped water leaves through the brick instead, and after a few winters the brick faces start spalling off in flakes and sheets.

So we match the mortar to the wall, not to whatever is easiest to mix. On old soft brick we use a lime-based mortar. Where a building has later patches in harder brick, we adjust the mix for that section rather than forcing one recipe across the whole elevation. Color and texture count too, especially on a front facade in a designated historic district, where exterior work goes through the city's Historic Preservation Commission review. We tell you at the first visit when a job is likely to need that review, so it doesn't surprise you halfway through planning.

Good repointing is mostly preparation. We cut the old mortar out to sound material, usually to a depth of about twice the joint width, using grinders on long bed joints and hand chisels near soft or chipped brick edges. Shallow scratching followed by a thin skim of new mortar is the repair that fails within a couple of winters, because the thin layer pops off at the first hard freeze. After cutting, we blow out the dust and dampen each joint, so dry old brick doesn't pull the water out of the fresh mortar before it can set.

We pack the new mortar in layers rather than one thick fill, pressing each lift hard into the back of the joint. When it reaches thumbprint hardness, we tool it to match the existing profile, whether that's flush, concave or a struck joint. Then comes the step that hurried jobs skip: curing. Lime mortar wants to stay damp for several days, so we mist it and shade it from direct sun and drying wind. Cold weather changes the schedule, since fresh mortar must not freeze before it has cured.

Not every wall needs repointing at once. The front facade takes plenty of weather, but exposed side walls, where a neighboring building is shorter or was demolished, often look worse because they were never built to face the street. Parapets and chimneys stand fully exposed above the roof and freeze hardest, so their joints usually go first. Up on the Heights, ridge-top wind makes every one of these problems worse. We'll show you which elevations need work this season and which can reasonably wait a few years.

Repointing often connects to other work at the same visit. A chimney with eroded joints may also need chimney crown and flashing repair, and a parapet with open joints usually leaks through its coping as well, which we handle under parapet wall waterproofing. Once fresh joints have fully cured, some owners add a breathable water repellent as part of exterior wall waterproofing. We only suggest that on brick that can still dry out through its face.