Chimney Repair in Somerville, NJ

The cap covers the top of the flue and keeps out rain, snow, birds and squirrels. Around the flue sits the crown, a slab of concrete or mortar that sheds water off the top of the stack. Without a cap, rain runs straight down the flue, rusting the damper and soaking the smoke shelf. Once the crown cracks, water gets past it into the brick, and freezing weather takes it from there.

The crew replaces missing or rusted caps, including one cap that covers every flue on a stack with more than one, and repairs or rebuilds cracked crowns so they slope water away and overhang the brick. A crown poured flat, or flush with the face of the stack, sends water down the brick; a sloped crown with an overhang throws it clear. On a framed chase, a rusted chase cover is replaced before it sends water down the inside of the framing.

Flashing is the sheet metal that closes the seam where the roof meets the chimney. When it rusts, pulls loose, or was only sealed with roofing cement instead of being let into the mortar joints, rain runs down the outside of the stack into the attic, and the first sign is often a brown stain on a ceiling or wall beside the chimney. The roof usually gets the blame, and in an older attic the water can travel along a rafter before it shows, so the leak is traced back to the stack before anything is sealed.

Depending on what the roofing and the brick will allow, the flashing is resealed, reset into the joints, or replaced, with step and counter flashing where the stack meets a sloped roof. If a roofer is replacing the shingles around the same time, the flashing work is coordinated so the roofline is opened once.

The liner protects the brick and the framing around the chimney from heat and combustion gases. In older stacks the clay tiles crack from heat, age and water, and pieces of tile in the firebox or at the base of a furnace flue mean the liner is breaking up. A cracked liner matters as much for a gas or oil appliance as for a fireplace. Damaged sections are repaired, or the flue is relined where the tiles are past saving.

Outside, mortar joints that freeze and thaw year after year open up and fall out, and bricks start to flake. Repointing replaces the failed mortar without disturbing the sound brick around it, and spalled brick is replaced. White staining on the brick, called efflorescence, shows that water is moving through the masonry and helps the crew trace where it is getting in.

Old brick calls for matching mortar. The soft brick in the older chimneys of Somerville, Rocky Hill and Millstone can be damaged by a repointing mortar harder than the brick itself, because the joint is meant to take the wear, not the brick face. The mortar for a repointing job is chosen with that in mind.

Most of this damage turns up during a sweep, since that is when someone is looking down the flue and standing at the top of the stack, so the evaluation covers the whole chimney before anything is recommended. You see photographs of what was found, and the work is quoted part by part. Rebuilding is reserved for a stack that is no longer safe, and if yours is one, you hear that directly.

Mortar and crown work need weather above freezing to cure, so those jobs go on the calendar from spring into late fall; a new cap or a loose piece of flashing can go in during any season. The evaluation and estimate are free. Registered as NJ HIC 13VH13654300 and veteran owned, AMG is licensed and insured and takes chimney calls from across central Somerset County 8 AM to 8 PM, 7 days a week. Where a long leak has also wet ductwork or an air handler in the attic, air duct repair or mold treatment and removal can follow the chimney work.