Chimney Flue Repair and Relining in Somerville, NJ

The flue's job changes, so it has to be checked against whatever vents there next. A new gas furnace venting up an old masonry flue may call for a stainless liner sized to it. A high-efficiency unit may vent through the wall and leave the chimney to a water heater alone. If nothing is left on the flue, it is capped. About one Rocky Hill home in nine still burns oil, and a small share of Montgomery and Hillsborough homes do too, so this comes up every year.

Timing matters. A liner has to match the appliance using it, so relining for the oil burner now and again for a gas furnace in a few years pays for the same job twice. If a conversion is on the horizon, a yearly sweep usually carries the oil flue until then, and it shows whether the old liner can hold out. Oil soot and scale also have to come out before a gas appliance goes on, since loose scale can fall and block the base of the flue. New Jersey's residential code says the lining has to be right for the appliance connected, following its listing and the maker's instructions.

Two furnaces sharing one chimney means a failure there affects two households, and any change to one appliance changes what the flue is doing for the other. In many Raritan two-families, the chimney serves both furnaces. When one unit replaces its furnace with a model that vents through the wall, the other is left with a flue sized for more exhaust than it now makes, and it cools and condenses the way a lone water heater does. The owner of a two-family may not hear about the change until the flue shows it.

Connections matter here too. Each appliance has to enter the flue as its installation calls for, and old connectors may have been patched over the decades. Rust holes in a connector leak exhaust into the basement. Rentals add their own complication, since half of Raritan's households and more than half of Somerville's rent, and a tenant may not know who to tell about a smell or a stain. Keep working carbon monoxide alarms on every level of both units, and plan any flue work with both sets of equipment in view.

A flood can leave silt and debris at the base of the flue, rust the connector and let water into the masonry, so a flue that sat in floodwater should be checked before the next heating season. A masonry chimney begins in the basement. In Manville, water that rose into a basement can enter through the cleanout door, and Ida pushed the Raritan to a record at the Manville gauge. The same goes for basements near Southside Avenue in Somerville, along the river in Hillsborough, and near South River Street in Millstone.

Silt can block the opening where the furnace or water heater connects, so the base gets emptied first. Then the flue is swept and checked, because wet masonry that freezes the following winter can crack a clay liner. A new connector, a liner section or a repair at the base usually settles it. If the equipment moved upstairs after the storm, the old flue may no longer vent anything, or may vent only a water heater, and that changes what it calls for.

A flue gets repaired when the damage is limited and reachable, and relined when damage runs along its length or its size no longer suits the appliance. Loose tile near the top, a joint at the crown and damage at the base can each be reached. Cracks in the middle of a two- or three-story stack cannot, short of opening the masonry, and on a plaster wall in an old house that is rarely a good trade.

A stainless liner dropped through the old flue gives a sound passage without disturbing the walls. New Jersey's code accepts clay lining and listed lining systems complying with UL 1777, and the appliance decides which applies. Where a flue has already been relined, the job is usually keeping the top sealed and the liner clean. Ask the town building department whether a permit applies to the relining before the work begins.

A chimney with no liner should not be left carrying exhaust, so the flue either gets a sound liner sized to the appliance or stops being used. The oldest brick and stone stacks in Rocky Hill, Millstone and the canal villages of Franklin were built before clay tile was common, and a sweep may find bare brick or stone from the firebox up. New Jersey's code says masonry chimneys shall be lined, and although that is written for new work, the reasons apply to an old chimney too: mortar erodes, heat reaches the framing and gases find the gaps.

Fireplaces in those houses can often stay in service with a new liner, though a historic flue may be odd in shape or offset, which limits the size that fits. The crew will tell you what was and was not reachable. You get photographs, a plain account and a free estimate. AMG, veteran owned and licensed and insured (NJ HIC 13VH13654300), takes flue calls at its Somerville location 8 AM to 8 PM, 7 days a week. Mention the age of the house and where the cleanout sits, and if a smoke chamber or a damper shares the problem, smoke chamber repair can be planned in the same scope.