Chimney Services in Glen Rock, NJ

What the numbers suggest for chimneys in Glen Rock

Census estimates place about 34% of Glen Rock's 3,696 housing units in buildings from 1939 or earlier and 41% in buildings from 1940 to 1959. Only about 10% were built in 2000 or later. With about 91% of units being detached single-family houses, most of these chimneys serve one household and one owner decides on repairs.

Heating is almost entirely utility gas, at about 89% of occupied homes, with electricity at about 8%. The Census tracks heating fuel, not fireplace use, so these figures say nothing about how often fireplaces are lit. They are a reminder that a fireplace flue and a heating flue can sit side by side in one chimney, which matters for dampers: a damper belongs only on a fireplace flue.

A fireplace that has been in place for 70 to 100 years has opened and closed its damper through countless heating seasons, and moisture coming down an uncapped flue reaches the damper first. Our guide to the parts of a chimney shows where it sits.

What decades of use do to a throat damper

A throat damper is a metal plate in a frame at the top of the firebox, opened and closed by a handle, lever or rotating rod. Over time the plate can warp, the hinge points can rust, and the frame itself can corrode. In a Fine Homebuilding article on flue-top dampers, the author describes a throat-damper frame that had rusted out and left a hole big enough for a raccoon to enter.

Things you can notice without taking anything apart:

• the handle is stiff, loose or will not move at all;
• the plate does not close fully, or you feel a draft with it closed;
• rust flakes or debris fall when it is moved;
• you can see daylight around the closed plate from below with a flashlight.

Do not force a seized damper. Forcing it can drop debris into the firebox or break the frame. With the damper open, a flashlight aimed up past it also shows whether the smoke shelf behind it is holding debris or rust flakes.

Repair, replace or seal at the top

1. If the frame is sound and only the hardware is worn,repairing the handle, pivot or plate may restore it.
2. If the frame is rusted through or the plate is badly warped,the throat damper can be replaced, though that work is done from inside a cramped smoke chamber.
3. If the fireplace flue also has no cap, or animals have been a problem,a top-sealing damper is worth considering. It closes down on top of the flue tile, is spring-loaded, and is opened with a stainless cable run down to the firebox, according to the Fine Homebuilding article. Closed, it also keeps animals out of the flue.
4. If the flue serves anything besides the fireplace,no damper of either kind belongs on it. Heating equipment flues must stay open.

We install top-sealing dampers and repair or replace throat dampers. Our guide to throat and top-sealing dampers compares them in detail.

Local questions

Sources

1. U.S. Census Bureau, American Community Survey 2020–2024 5-year estimates (tables B25034, B25040, B25024), via Census Reporter
2. Fine Homebuilding: Installing a Flue-Top Damper (PDF)