Chimney Services in Hazlet, NJ

What the numbers suggest for chimneys in Hazlet

About 34% of Hazlet's 7,957 housing units date from 1940 to 1959 and 39% from 1960 to 1979, according to Census estimates; only 6% were built in 2000 or later. Houses from those decades are likely to have brick chimneys with clay tile flues, sometimes holding separate flues for the fireplace and the furnace, as described in chimneys with more than one flue.

About 86% of occupied homes heat with utility gas, 8% with electricity and 3% with fuel oil. When a high-efficiency furnace that vents out the side wall replaces the old one, a water heater may end up as the only appliance on a flue built for two. The orphaned water heater problem explains why that matters.

Detached houses account for about 82% of units. The estimates are township-wide and say nothing definite about a single chimney.

Reading the mortar on your chimney

Mortar is meant to be the weaker, renewable part of a brick wall. The National Park Service calls mortar joints sacrificial and expects them to need repointing at some point. The Brick Industry Association's maintenance note lists the conditions that call for repointing: mortar eroded deeper than 1/4 inch, crumbling mortar, voids, hairline cracks in the mortar and cracks between brick and mortar. It also groups chimneys with parts of a building whose more severe exposure may require repairs at shorter intervals.

From the ground, with binoculars, look for:

• Joints that sit recessed and shadowed behind the brick face.
• Sand or mortar grit on the roof below the chimney or in the gutter.
• Thin gaps along the edges of bricks where mortar has pulled away.
• Patches of brighter, newer mortar, which mark earlier repairs worth asking about.

Where you can reach a joint safely, such as at the base of an outside chimney, press a key into it. Sound mortar resists; sandy mortar crumbles. Leave anything on the roof to someone with the right equipment.

Where the chimney runs through an accessible attic, look at the brick there with a flashlight after a rain. Damp patches or white powdery deposits suggest water is moving through the masonry; white staining on brick explains those deposits.

What repointing involves, and when it is not enough

Repointing removes damaged mortar and replaces it. BIA's note calls for raking joints to a uniform depth of at least twice the joint width, generally 3/4 inch, or until sound mortar is reached, and for repointing mortar whose compressive strength is equal to or lower than the original. Mortar that is too strong can damage the surrounding brick. The NPS brief says a good repointing job should last at least 30 years.

Repointing fits when the bricks themselves are sound. Loose or displaced bricks, a leaning stack or widespread flaking move the discussion toward a partial rebuild; see repair or rebuild a chimney? The crown, cap and flashing are checked at the same time, because water entering at the top of the chimney keeps working on the joints below. The work is planned under masonry repair and repointing, and crumbling mortar joints goes deeper into the subject.

Local questions

Sources

1. U.S. Census Bureau, American Community Survey 2020–2024 5-year estimates (tables B25034, B25040, B25024), via Census Reporter
2. Brick Industry Association, Technical Note 46: Maintenance of Brick Masonry (PDF)
3. National Park Service, Preservation Brief 2: Repointing Mortar Joints in Historic Masonry Buildings (PDF)