What's Included
Fitting a top damper to your Bertha chimney
Bonding the damper to the flue
In the Lock-Top installation instructions, the installer spreads a 1/4 inch bead of the furnished adhesive around the top of the chimney opening, centers the damper, presses the frame down firmly and fills any gaps with adhesive for a proper seal. The instructions allow the adhesive 24 hours to set before the damper is used.
Our installers follow the maker's instructions for the damper chosen for your Bertha chimney, including its adhesive and its set time. We tell you when the fireplace can be used again, and the damper is not operated until the adhesive has set.
The safety device supplied with some dampers
Some top dampers come with a safety device built around a fusible link on the lid. The Lock-Top instructions state that this device must be installed for the warranty to be in effect, and they show how it is assembled under the lid before the damper goes on the chimney.
Our installers fit every part the maker supplies for the damper on your Bertha chimney, including any safety link, and follow the assembly order in the instructions. Leaving out a supplied part can void the maker's warranty, which is protection you are entitled to keep.
Fireplaces with a decorative gas appliance
A vented decorative gas appliance placed in a wood-burning fireplace changes the rules for the damper. One such appliance manual, written to ANSI Z21.60, comes with a damper clamp that has to stay permanently in place, holding a minimum opening so the damper can never shut completely, and it says the chimney damper must be fully opened while the appliance runs.
A damper built to close tightly at the top works against that requirement, and the Lyemance listing warns against using its top damper with such appliances because a damper left closed could let carbon monoxide back up into the home. If your Bertha fireplace has one, our team explains the safe options before recommending any damper.
Closing the air path through an idle chimney
An open or leaky damper leaves a path between the room and the outdoors. Warm air rises out of the flue, and at other times outside air sinks down it, bringing the smell of the chimney with it. A top damper that seals at the top closes that path whenever the fireplace is not in use.
Our team tests how well the existing damper in your Bertha fireplace closes before recommending a replacement. If it still seals, you keep it. If it does not, the top damper's gasket gives the fireplace a proper closed position again.
