Ask Us About Repairing Your Flue Liner with HeatShield®

A flue liner that is intact and properly functioning is vital if your chimney is to provide minimal risk and the level of functionality and draft that you need in your home.

A flue liner’s job is to:

  • facilitate the draft that takes combustion byproducts up through the chimney
  • prevent toxic carbon monoxide from leaking into your home air supply
  • buffer nearby combustible materials from the high heat that’s produced by your fireplace or stove
  • protect your masonry structure from the caustic elements of combustion byproducts

Many chimneys are lined with clay tile flue liners, and with regular care and maintenance, these liners can provide years of service. However, over time and with use:

  • clay tiles can crack due to sudden occurrence high heat event (i.e. chimney fire)
  • the mortar joints in the liner can deteriorate and degrade causing gaps between the flue tiles
  • poorly-built chimneys can have unsealed joints between the liners from the time they are built

Damaged or poorly installed clay tile liners are out of compliance with most codes and industry standards because they increase risk and are inefficient. They need to be repaired or replaced sooner rather than later.

To repair and restore damaged clay tile flue liners, Blue Sky Chimney Sweeps recommends and provides the application of HeatShield® cerfractory sealant for qualifying structures. HeatShield® is made to withstand the high temperatures in your chimney (more than 2900 degrees Fahrenheit).  When properly applied by professional technicians (like the ones employed by Blue Sky Chimney Sweeps), it creates a smoke-tight and air-tight seal in your flue. HeatShield carries a 20-year material warranty.

Heatshield Joint Repair Application showing the inside deterioration of a chimney liner with missing mortar and gaps that were repaired with HeatShield.

Heatshield Joint Repair Application

Heatshield Resurfacing showing inside of tile flue with missing mortar between tiles, spalling/bracked flue tiles and then gaps, cracks and spalling repaired with HeatShield.

Heatshield Resurfacing

Heatshield Cecure Sleeve Relining showing the HeatShield surface and the CeCure Sleeve.  At the bottom it show the unlined brick flue.

Heatshield CeCure Sleeve Relining

How Is HeatShield® Applied?

Blue Sky Chimney Sweeps’ technicians will inspect your flue liner to assess the level of damage. If your chimney is a good candidate for this repair, we will recommend the HeatShield® system that can most effectively repair that damage.

HeatShield® Joint Repair

Flue liners that are largely intact, but have damaged or deteriorated mortar joints, can be repaired using HeatShield®’s Joint Repair System. To apply the product, Blue Sky Chimney Sweeps’ technicians will use a specially-designed foam applicator (that’s custom-fitted to your chimney) to fill and smooth all of the cracks and voids in your liner. Once every damaged area is repaired, we’ll inspect to ensure that your flue liner is fully crack-free and gap-free.

HeatShield® Resurfacing System

When damage extends beyond the mortar joints to cracked or spalling tiles, we’ll opt for HeatShield®’s Resurfacing System, which allows us to address the entirety of the flue liner. After applying a preparatory coat to your flue liner, we layer a quarter inch-thick coat of HeatShield® material using a method called “slip casting.” Simply explained, a custom sized foam applicator is pulled up through the whole flue with a winch, leaving the correct thickness of HeatShield® material as it travels up the chimney. When the sealant layer dries, we’ll carefully inspect the flue to make sure you have a smooth, smoke-tight chimney.

HeatShield® Makes a Relining Product Too

If your clay tile liner is too damaged for repair, Blue Sky Chimney Sweeps’ technicians can talk to you about several different relining options, including the installation of a new stainless steel flue liner or the use of HeatShield®’s CeCure Sleeve Relining System. We’ll help you find the best new liner for your system and your home, and install it properly.

If your clay tile flue liner needs repairs, Blue Sky Chimney Sweeps may be able to renew it using HeatShield® cerfractory sealant. Call us today to talk about your chimney and your options or click here to schedule an appointment online.


Stainless steel liners offer another chimney lining or relining possibility. We can advise you about the suitability of this product option for your situation.