Thermocrete Ceramic Sealant – The Solution To Older Masonry Chimneys Built Without Liners

Character and quality-workmanship are just some of the things we value in older homes – but there’s one common thing that we don’t like in older homes: unlined chimneys. Unfortunately, most homes built before 1922 were built with unlined chimneys. Not only is an unlined chimney incredibly inefficient, it’s also incredibly dangerous.

According to tests conducted by the National Bureau of Standards (in both 1940 and 1980), chimneys without liners are so unsafe that building a chimney without one was described as “little less than criminal”.

Why Do I Need A Chimney Liner?

Chimney liners are responsible for containing and removing dangerous gases and byproducts that result from combustion, so that they don’t seep back into the home or corrode the chimney itself. They also work to keep heat from transferring to nearby combustibles. Without a chimney liner, your appliance will not work as it was intended to, and your risk of fire, carbon monoxide poisoning or other respiratory and health-related issues are greatly increased.

What Are My Options If My Masonry Chimney Was Built Without A Liner?

If your chimney was built without a liner, the experts at Northeastern Masonry & Chimney can take a look at your system and discuss your options with you. We often find that Thermocrete Ceramic Flue Sealant is the best option because it can strengthen and seal the chimney without significantly altering the size of the chimney interior. This is important because every appliance requires a certain flue size in order to function properly, and many times retrofitting a stainless steel liner into an older chimney can leave the homeowner with a flue that is too small for the appliance.

What Is Thermocrete?

Thermocrete is a ceramic flue sealant that works to coat the interior of the chimney and seal cracks and gaps. The product is sprayed onto the masonry surface in layers, and is designed to:

  • stand up to high levels of heat
  • strengthen the chimney
  • resist damage from the corrosive and acidic byproducts of combustion
  • increase efficiency by providing a smooth surface

We typically use this product for historical chimneys and chimneys that have clay liners in need of some TLC.

Call Northeastern Masonry & Chimney Today!

If your chimney was built without a liner or your clay liner needs a little restoration work, call the experts at Northeastern Masonry & Chimney! We are trained in the application of Thermocrete Ceramic Flue Sealant and guarantee all of our work. Not sure if Thermocrete is right for your system? Don’t worry – we will be more than happy to help you sort through your options and make the best decision for your home and family. Give us a call today at 518-767-9315 or use our convenient online scheduling form!


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