Chimney Liner Question

The most important thing to do when installing your chimney system is to get the correct sizing for the vent. Installing an improperly sized system can lead to inefficient venting. When an over-sized vent is installed, your chimney system will not allow the heat to warm your home before exiting up the chimney. This will result in you losing a great deal of heat up your chimney, severely decreasing the efficiency of your heating unit and increases your heating costs. When having an under-sized vent it may not allow the air to rise properly and in some cases cause the smoke to back up into your home. Choosing a proper size system based on your needs is critical to a reliable and efficient chimney system for years to come.
System Problems
System Problems:
A high efficiency appliance which will produce more heat for your home while using less fuel can cause a problem with its colder exhaust temperature and less exhaust is produced to keep the chimney warmer to conduct drafting. No one wants to waste heat up the chimney, but a certain amount of heat is necessary in order to provide the draft that makes the venting system work, and to keep the chimney walls warm enough to prevent condensation of the exhaust gases. If the flue temperature becomes too low, two separate but interrelated problems may occur– improper drafting and water condensation. Improper drafting will lead to hazardous gases possibly backing up into your home and the water condensation can lead to creosote build-up and the eventual corrosion of your chimney. Creosote can lead to chimney fires, blockage and corrosion of the flue, which can reduce performance and the life of your chimney system.

Other symptoms that could point to a venting system problem include:

  • Damp patches on interior or exterior walls
  • Peeling wallpaper
  • Blishered paint
  • Stains on the ceiling around the chimney
  • White stains (efflorescence) on the outside of the masonry chimney
  • Eroded mortar joints
  • Crumbling bricks


The dangers of an improperly installed or damaged system can lead to risks of carbon monoxide poisoning and house fires. Chimney fires happen when creosote builds up in the flue and ignites. These fires can rage at temperatures up to 2000 degrees and roar just inches away from your home. The intense heat or sparks from the fire through a cracked flue tile can ignite the surrounding materials, quickly turning a chimney fire into a house fire.
Carbon monoxide (CO) is a colorless, odorless gas. Sometimes an early warning is flu-like symptoms, but carbon monoxide can cause brain damage and death with no warning. A damaged chimney flue poses a real threat of carbon monoxide poisoning, because this gas can escape through the smallest crack. Also, a partial or complete collapse of the clay flue liner can block the flue, and quickly fill the house with deadly gas. Sadly this tragedy occurs in homes across the country every year.

Regular cleanings and a straight system will help to protect against the dangers to your chimney system. These systems will provide a physical barrier between the vented gases and your home. In short, prevention and upkeep can significantly increase your family’s safety and improve the long-term reliability of your system.