Condensation Inside Chimney Liner

Condensation inside the chimney can cause a leaking chimney.

Condensation inside chimney liner.

When a fire is started the new warm air moving into the chimney comes into contact with the cold chimney walls causing condensation. Usually a new liner will resolve this problem. On occasion we have identified the wetness around a chimney to be due to the condensation of the airborne moisture in the exhaust gases discharged by the furnace on the cold chimney walls. You insert one end of the run of the tee into the liner where the liner emerges from the chimney.

The wetness on the outside faces of the chimney occurs when the condensate migrates through the mortar. Instead of allowing moisture to evaporate the condensation may just soak the brick interior and then drip down. Condensation can occur when ascending combustion gases meet cooler temperatures in higher parts of the flue finally dropping below the dew point. Leaks in the chimney structure a condensation effect also can happen within the chimney itself.

In some cases the heat from the fire will cause the condensate to evaporate. You will need to protect the insert from moisture problems. A chimney cap had been added to the chimney above the furnace flue when the roofing had been done to complement the existing cap above the fireplace flue. This is often a problem when the liner used is not the ideal size or material.