Chimney Rebuild in Cherry Hill, NJ

It has to come down when the masonry itself has failed and new mortar would have nothing sound to hold. The clearest signs are a stack leaning out of plumb, loose bricks that move by hand, brick faces spalled away across large areas, and joints so deep that the courses no longer bear on each other. Cracks that run through the bricks in several places point the same way.

Repair still wins in many cases. If the bricks are hard and the mortar is the only thing failing, repointing is the honest recommendation, and if the trouble is limited to the top few courses, those can be relaid without a full rebuild. Lean deserves particular care, because a stack leaning above the roof may be a masonry problem while a stack leaning from the ground up may have a footing problem. The inspection looks at the chimney from the roof and the firebox before anyone proposes taking brick down, and you will be told plainly which side of the line yours falls on.

It starts wherever the masonry turns sound again, which is most often the roofline. A partial rebuild starts at the crown, takes the brick down to sound masonry and lays it back up. A rebuild from the roofline replaces the whole exposed stack, and that is the common version on a chimney that has weathered evenly. A full rebuild from the ground up is rare, kept for a chimney with a failed footing or damage through its full height.

The parts that meet the masonry change at the same time. The flue tile above the work comes off and goes back or gets replaced, a new crown goes on with a slope and a drip edge, and the cap is refitted. Flashing is cut out and reset into the new joints, so a rebuild is often planned around roof work if the shingles are due. If the flue has been unlined or the tile has failed, a liner can go in during the rebuild, when access is at its easiest.

New Jersey's residential code calls for a chimney to stand at least 3 feet above the point where it passes through the roof, and at least 2 feet higher than any part of the building within 10 feet. A chimney that was built lower than that, or one sitting near a dormer or a later addition, may raise a question at rebuild time, so measure before the plans are set. Height also affects draft, and a short chimney next to a steep roof is a common cause of smoke trouble.

Other parts of the code touch this work as well. It requires a cricket, the small peaked diversion that keeps water from pooling behind a chimney, where the stack is more than 30 inches wide parallel to the ridge and does not meet it. It also sets out an airspace of 2 inches between an interior masonry chimney and nearby combustible framing. How those rules apply to an existing chimney being rebuilt is a question for the town. Check with the town building department on permits, and on what it will want to see, before work is scheduled.

A framed chase can be repaired or re-sided, but what stands inside it is a factory-built system and not a masonry chimney. In many houses around Voorhees, Evesham and Mount Laurel, the box on the outside of the wall is wood framing and siding with a metal flue running up the middle. Water coming through a rusted chase cover can rot that framing, and the work then has more in common with carpentry than with masonry, along with a new cover at the top. In townhouse rows, the association may own the structure above the roofline, so start there.

The metal flue has to stay within its listing, so it is not swapped for brick without replacing the fireplace itself.

A rebuilt chimney can come close, and on a historic house that match is part of the job from the start. Sound old brick can often be cleaned and reused on the face of the stack, with new brick of the same size and color working on the less visible sides. Mortar gets the same care. The National Park Service's guidance is that new mortar should stay softer and more vapor permeable than the brick it joins, and its color and joint profile should follow the original, so a rebuilt top does not look like a patch from across the street.

Approval comes before the first brick is lifted. Haddonfield wants a Certificate of Appropriateness for changes to a building's exterior appearance in its historic district, with the Historic Preservation Commission and the Planning Board both involved, and rebuilding a chimney in a different form falls squarely into that. Moorestown sends exterior changes on its protected stretch of Main Street and part of Chester Avenue to its own commission, and Olde Marlton in Evesham is regulated by the township. The crew puts what it proposes in writing, which gives you something to take to those conversations. For masonry stacks, chimney repair is the first thing to weigh, and chimney cleaning shows what the inside looks like before the decision. The company behind the work, AMG Duct Cleaning Cherry Hill, is licensed and insured and veteran owned, and its free estimate on a rebuild comes with photos from the roof and a plain explanation of why the work is or is not called for.