Chimney Repair in Readington and Hunterdon County

The cap keeps rain and snow from falling straight down the flue and keeps birds, squirrels and raccoons from moving in, which on a rural lot is a real concern. A stack that carries several flues takes a cap spanning all of them, the idle flue included, since that is the one nobody thinks about until a nest drops into the firebox. The mesh is sized to stop animals without choking the draft.

The crown is the cement or mortar slab that seals the top of the chimney around the flue. Many were poured flat, with no slope and no overhang, and they have been shedding water into the brick below ever since. A cracked crown is sealed where the damage is minor and rebuilt where it is not, with a slope that runs water off and an edge that drips clear of the brick face. Where the stack passes through the roof, metal flashing laps under the shingles and turns up into the brick joints. Once it lifts, rusts through or was cut short when the roof was last replaced, water runs down the outside of the chimney into the attic, and the stain on the bedroom ceiling gets blamed on the shingles. Resealing fixes a loose edge; flashing that has failed along its length is replaced.

Repointing replaces mortar that has cracked, crumbled or fallen out of the joints. The old mortar is raked out to sound material and the joints are packed again in layers, so the new mortar bonds deep instead of sitting as a skin on top. On an older chimney the choice of mortar matters as much as the work. Brick laid before modern cement mortars is often softer than the mixes used now, and a joint harder than the brick around it forces the brick to take the stress of each freeze, so the faces crack and pop off. The new mortar is matched so the joint stays the weaker part and can be repointed again someday.

Bricks whose faces have spalled away are cut out and replaced with the closest match available. Farmhouse stacks built of stone get the same treatment at the joints. White staining on the brick, called efflorescence, is salt left behind as water moves through the masonry, and it tells the crew where to look for the entry point above it. Fixing the joint without stopping that water only resets the clock.

The liner is the inner shell that carries smoke and exhaust up the stack and keeps that heat and those gases off the brick and the wood nearby. Clay tile liners crack with age and with the heat of a chimney fire, and the joints between tiles erode, especially behind an oil boiler that has sent its exhaust up the same flue for decades. Some of the oldest chimneys in the county were built with no liner at all. A cracked or missing section can sometimes be repaired, and where the old liner is past saving, a new liner sized to the appliance it serves is installed.

Equipment changes create their own liner work. When a furnace is swapped for a high-efficiency unit vented out the side of the house, a water heater left venting alone into a big masonry flue can run too cool to draft, and a liner sized to the water heater is the usual repair. Down at the hearth, a damper rusted stiff by years of water coming down an uncapped flue is freed or replaced, and cracked firebrick or open joints in the firebox are repaired so heat stays where it belongs.

In Flemington, the borough's Historic Preservation Commission reviews applications from owners in the historic district for repairs, alterations and renovations, and Readington's commission, for its part, advises on alterations to historic buildings across the township's villages. Checking with the borough or township office before exterior work on a visible chimney avoids surprises, and the crew matches brick, stone and mortar either way. Mortar also wants mild weather to harden properly, so repointing and crown rebuilds are best booked between spring and late fall, while a cap or a flashing repair can go in through most of the year.

The evaluation covers the whole chimney, up top whenever the roof can be stood on safely and down at the firebox, and you get photographs of what the crew saw. Most chimneys are repaired one part at a time, cap, crown, flashing, joints or liner. Tearing down and rebuilding is the answer only for a stack that is no longer sound enough to stand or to vent safely. A sweep is often where the damage first comes to light, because a chimney cleaning is the one visit that puts eyes inside the flue and on top of the stack. Estimates are free and scheduled 8 AM to 8 PM, 7 days a week through the Readington location; AMG is veteran owned and works licensed and insured under New Jersey HIC registration 13VH13654300.