Chimney Crown and Crack Repair in Readington and Hunterdon County

The top of a chimney cracks first because it is wettest, coldest and least protected. The crown takes rain and snow on its flat face, and the courses under it have no heat from the house to dry them. Crowns on many older stacks were never built for the job. They were troweled on from leftover mortar, nearly flat and with no overhang, so meltwater sits on them and runs down the brick face. Fine lines appear first, then a split from the flue tile to the edge, then pieces that lift off in the spring.

From the driveway, look for a crown with a dark edge, brick faces flaking off in the top few courses, and white salt stains spreading down from the corners. Mortar sand in the gutter or on the shingles is another clue. Cracks low on the stack that stair-step along the joints deserve a closer look, since they can mean the chimney has moved.

A properly rebuilt crown slopes away from the flue, overhangs the brick with a drip edge and stands free of the tile on a bond break. New Jersey's residential code asks for those same things on a masonry chimney: a concrete, metal or stone cap sloped to shed water, a drip edge, and a caulked bond break around any flue liners. The break matters on an oil or wood flue in particular, because the tile heats and swells with every burn cycle, and a slab cast tight against it cracks.

Fine cracks in a sound slab do not call for any of that. They can be sealed, and sealing them early is the smallest repair a chimney will ever get. A crown that has gone soft, or that was built flat, comes off and goes back properly. Farmhouse stacks with two or three flues get a break around each tile. Plan the pour for mild weather, since concrete and mortar set poorly near freezing, and a crown left until late fall may have to wait for spring. In Flemington's historic district, ask the borough first about any change in the crown's shape that can be seen from the street.

Yes, cracks in a stone chimney are usually repaired at the joints, since the stone tends to outlast the mortar around it. Old fieldstone stacks were often laid in soft mortar that wears back from the face over time, and water then travels through the wall behind it. Repointing removes the failed mortar to a sound depth and packs new mortar in layers. The mix should be softer than the stone and suited to the old work, so that the joint rather than the stone takes the movement of each freeze. Hard portland mixes on old stone hold water in the wall and can pop the stone faces off.

Loose stones are reset rather than glued in place, and a stone that has split is replaced with one close in color and shape. The same care applies to soft old brick in a village house. A joint repair on a brick chimney in Stanton or Oldwick is judged by how well it matches the color and profile of the joints around it, because a bright band of new mortar on an old stack shows from the road. Cracks that run straight through the masonry, or a section that has bowed outward, are a sign to stop and look at how much of the wall is still doing its job.

Yes, exhaust can damage a chimney from the inside when it condenses on cool flue walls and the acidic moisture works into the tile and mortar. An oil boiler leaves scale that flakes off and collects behind the cleanout door. A propane appliance venting into old masonry is wetter still, and an oversized flue stays cool enough for that moisture to soak in. Staining that bleeds through the outside of the chimney high on the stack, far above any rain leak, is a sign that this is happening. Repointing the outside will not last if the flue keeps wetting the wall from within.

So the flue gets checked before the masonry work is settled. Chimney cleaning clears the soot and scale and lets the crew see the tile, and any liner or flashing work is handled under chimney repair. A homeowner in Delaware Township or East Amwell who is switching fuels should raise this before the new equipment goes in, since a changed appliance can change what the flue does to the brick.

Yes, an old masonry chimney near the epicenter deserves a look, because a crack from shaking does not always show from the ground. The quake caused little damage across the region, but it brought down the upper part of Taylor's Mill on Rockaway Creek, which shows what shaking can do to old masonry. A split crown, a joint opened near the roofline or a cracked flue tile can sit unnoticed until water finds it. Stacks in Tewksbury and Readington, along with the older villages nearby, are the first ones to think about.

The inspection comes from both ends, the roof when it can be walked safely and the firebox, and you get photographs of what the crew finds. Estimates are free, and the crown and crack work covers Readington, Tewksbury, Flemington and the rest of Hunterdon County. AMG is a veteran owned company, licensed and insured in New Jersey under HIC 13VH13654300, and for a larger masonry job you should ask the town building department whether a permit applies.