For chimneys more than 40 inches 1016 mm wide two additional no.
Fireplace insert without chimney liner.
Without a chimney liner your chimney will be in danger of overheating which can cause your chimney to combust.
The chimney draft is created like a tornado when a warm front meets a cold front.
4 vertical bars shall be provided for each additional flue incorporated into the chimney or for each additional 40 inches 1016 mm in width or fraction thereof.
While the original masonry fireplace and clay flue liner can be used as a passageway the original chimney flue can not be used to vent the wood burning insert.
Please remember these liners are sold in 5 increments 15 20 25 so for instance an 18 chimney will need a 20 liner.
A connector and chimney system designed with the wood burning insert in mind would be a necessary addition to the wood burning stove inserted into the fireplace.
Stoves inserts connected to fireplaces.
This is why it is important to have a wood burning fireplace insert installed with its own round properly sized and insulated chimney liner pipe.
A liner going to an insert or stove in the fireplace will be measured from the top of the chimney to the top of the insert or stove or the center of the hole on the back of the stove.
You don t want to play with fire and if you don t have a liner then you re in danger of burning down your house.