HeatShield® – Chimney Flue Liner Repair Product

You have probably never heard of HeatShield® but it may be the answer to correcting hidden dangers in your chimney liner. When the clay liner in older chimneys cracks, it allows smoke, embers, and sometimes fire to escape through the liner into the ceilings and attic space of your home. You can imagine what can happen once smoke, embers, and fire are transferred to those areas.

HeatShield Infographic with diagrams of how it restores your chimney clay flue

One of the only options you would have until now is to replace the entire chimney liner with a stainless steel liner or a cast masonry liner that are both costly and time consuming. With HeatShield® you now have the option to restore your chimney’s clay flue liner instead of the expensive cost of rebuilding or relining.

How do you find out if your liner has these dangerous issues? The answer is to make sure you get a thorough chimney inspection. This should include running a camera up through the chimney liner and closely inspecting the walls of the liner itself. Through this process, we are able to see the details that reveal the hidden dangers that hide within the walls.

The more you know how a chimney works, the better you understand why it needs to be properly maintained. It’s so easy to get caught up in the warmth of a roaring fire and to forget it is also a potential hazard if not taken care of properly.

A few things that can cause serious issues if not resurfaced and restored.

  • Deteriorated mortar between clay flue liners
  • Cracked clay liners
  • Spalled clay flue liners or tiles (flaking)
  • Eroded clay liner
  • Gaps and holes between flue tiles
  • Cracked flue tiles

Once the HeatShield® has been applied, it will restore the integrity of your chimney flue liner to vent the hazardous gases out of your home the way your chimney is supposed to do. We restore the proper functionality of your fireplace so you can enjoy your fireplace and rest at night knowing you have done everything you can to keep you and your family safe.

We do this with the HeatShield® process that eliminates the hazards and draft problems caused by gaps, cracks and spalling in otherwise sound masonry chimneys. These are all things you cannot readily see unless an inspection is done.

Though our number one reason for offering the HeatShield® option is for safety purposes, you should also consider the fact that a chimney that is stressed or in distress is one that is also not working efficiently. Those small gaps and cracks allow excess air into your chimney, slow the updraft and make it harder for smoke and gas to rise up and out. That means that the fireplace, wood stove or furnace will perform poorly, resulting in the loss of heat efficiency.

According to the Chimney Safety Institute of America, (CSIA.org), problems such as gaps, cracks and spalling (flaking) in your chimney’s flue can present serious risks to your home and family, because your chimney can no longer perform its intended function, which is to safely contain and vent the products of combustion to the outside of your home.

The National Fire Protection Association (NFPA) states, “If the flue liner in a chimney has softened, cracked or otherwise deteriorated so that it no longer has the ability to contain the products of combustion (i.e., heat, moisture, creosote, and flue gases), it shall be removed and replaced, repaired or relined…” NFPA 211-Standard for Chimneys, Fireplaces, Vents and Solid Fuel-Burning Appliances (2010).

As you can see the two major organizations CSIA and NFPA are well aware of the issues caused by allowing the deterioration of a chimney’s liner. It’s also written into the building codes and fire standards that chimneys should be structurally sound, durable, smoke-tight and capable of conveying flue gases to the outside completely and safely. This is just not about new construction but any residential or commercial structure that is fitted with a fireplace, woodstove or furnace appliance of any type.

Every property owner should start with an inspection to find out if this is something they even need to worry about. Most of the time, chimneys that have been properly maintained are fine unless something has happened to damage it outside of normal use. This could include weather incidents, tree damage or, on occasion, damage done by animals, including birds and rodents. Having the option to restore your chimney with HeatShield® gives you and us a great way to restore function for safety and efficiency without the added hassles and cost of rebuilding the chimney with a new liner.

If you feel this might be something you want to look at, please contact us and let us know.


Are you a candidate for a stainless steel liner; just one of many relining and restoration services provided by Owens Chimney Systems.