How HeatShield® Cerfractory Sealant Can Restore Your Chimney

Whether your existing clay tile liner is in need of repair or a complete resurfacing – HeatShield® Cerfractory Flue Sealant can help! The product — which combines ceramic and refractory mortar – is designed to stand up to moisture, temperatures exceeding 2900 degrees F, and even the acidic byproducts of combustion. In fact, the system comes with a 20-year warranty when professionally installed.

How Does HeatShield® Work?

HeatShield® works by filling in holes, cracks and gaps and creating a seamless, smooth liner surface that encourages draft. When a liner is deteriorating, crumbling and cracking, it can slow down the removal of dangerous gases that result from combustion. As these gases linger in the flue, a couple of things can happen:

  • They can escape back into the home (seeping through cracks and gaps and even backflowing into the home)
  • They can cool and settle on the flue walls in the form of creosote and damaging water vapor

A cracked and deteriorating liner can also allow:

  • heat to transfer to nearby combustibles, which could easily start a house fire
  • the acidic byproducts of combustion to corrode the chimney walls
Heatshield resurfacing application showing inside of chimney with missing mortar and crackes and spalling

What Is The Process Like?

When our expert technicians use the HeatShield® system to restore your flue, they will first video scan your flue liner and document all damage or areas of concern. If there are only a few areas in need of repair, a primer will be applied to those areas, followed by the HeatShield® product. Once the product is applied, a foam applicator is used to ensure that the holes, cracks or gaps are filled and that the product is smooth and even.

If our initial video scan reveals more extensive damage and the entire flue needs resurfacing, our technicians will place a foam applicator at the base of the flue and apply a primer to the entire liner. Once the primer is dry, the product will be poured into the flue, and the applicator will be pulled up through the flue, sealing cracks and gaps and smoothing the product as it goes.

After either process, a video camera will be used to verify and document the results of our work. We want you to see the difference HeatShield® can make in your flue liner!

Make Your Appointment Today!

If your flue needs repair or resurfacing, our certified and trained professionals can use HeatShield® to properly repair and renew your liner’s surface, regardless of fuel type. Don’t put your home and family at unnecessary risk – call Northeastern Masonry & Chimney today, or click here! We can ensure that your flue is functioning properly and efficiently!


The chimney and flue for your oil-fired appliance need regular cleaning and maintenance, just like the chimney for your wood-burning appliances. A professional inspection will also tell us if the chimney needs to be relined, so talk with us about all the possibilities.