Achieve Peak Safety & Efficiency Levels With HeatShield® Flue Repair & Reline

Is your chimney a poor performer? Is the old clay tile liner riddled with safety and efficiency threats like holes, cracks, and gaps? For decades, clay tile liners were the liners of choice, but over time, these types of liners spall, crack, and deteriorate, leaving open areas and rough surfaces that reduce draft and air flow and allow heat from the fire to transfer to nearby combustibles (like framing and walls).

Without a thorough inspection, it can be nearly impossible to see this damage and identify these safety threats, but here at CinderBox Chimney Services, we use video scanning equipment to get a visual of the entire chimney flue — top to bottom.

If your flue liner is in bad shape, you may be thinking that the only option is to have any damaged clay tiles removed and replaced (which can be timely, messy, and costly) or have a new stainless steel liner installed. Well, while that may have been the case in the past, today, we’re pleased to say you have other options with HeatShield®.

Graphic of HeatShield Joint Repair Application.  Missing Mortar between flue tiles and Gaps repaired with HeatShield

Heatshield Joint Repair Application

Graphic of Heatshield joint repair application.  At the top of the chimney you can see missing mortar between flue tiles and spalling/cracked flue tiles.  At the bottom of the chimney you can see the gaps, cracks and spalling are repaired with HeatShield.

Heatshield Resurfacing

HeatShield CeCure Sleeve Relining System.  The graphic shows where the HeatShield repairs are, the CeCure Sleeve and the Unlined Brick Flue.

Heatshield CeCure Sleeve Relining

HeatShield® is a cerfractory flue sealant liner system that works to restore clay tile flue liners in one of three ways:

  • Joint Repair — Sometimes the clay tiles themselves are still in good condition, but the mortar joints between the tiles are cracked, receding, or deteriorating. When this is the case, we can apply HeatShield’s cerfractory flue sealant mixture directly to the mortar joints and smooth and seal the surface with a specialized foam tool. These now smooth, filled mortar joints serve to strengthen and insulate your flue liner and provide a safety boost to your system.
  • Resurfacing — Other times, the cracking, gapping, and deterioration is more widespread. In these situations, we can totally resurface the flue with HeatShield®. We start by using a specialized foam tool to apply a “tie coat” to the flue. Once that coat dries, we apply the HeatShield® cerfractory flue sealant mixture and smooth and seal the surface with a specialized foam tool. The result is an even, level, insulated, smoke-tight, and draft-friendly flue surface, top to bottom.
  • Relining — For flue liners that need more than a little surface repair, we can use HeatShield’s CeCure® sleeve relining system, which combines the strength and insulation of stainless steel and ceramic with the strength and insulation of the cerfractory flue sealant. First, we apply a “tie coat” and allow it to dry, just as we do when we’re resurfacing the flue with HeatShield®. Next, we apply a coat of the cerfractory flue sealant, allow it to dry, and then lower a custom-fitted CeCure sleeve down into the flue. This sleeve is made of ceramic and stainless steel and is incredibly insulating. Once the sleeve is snugly in place, we pour another coating of the cerfractory flue sealant, sandwiching the sleeve between two layers of HeatShield®. The result is a stronger, smoother, better insulated flue surface that can withstand temperatures of 2900+ degrees F.

But it’s not just HeatShield®’s restorative properties that make it such a great system — it’s also:

  • resistant to corrosion
  • approved for venting all fuels
  • UL tested, listed, and certified
  • eco-friendly
  • long-lasting

In fact, as long as you keep up with annual chimney maintenance, HeatShield® is covered by a 20 year warranty.

Schedule Your Appointment With An Educated, Experienced & Reliable Chimney Pro Today!

If you’re as excited about HeatShield® as we are and would like to learn more or schedule an inspection, flue repair, or reline with one of our CSIA-certified chimney professionals, call 317-442-8440 or use our online appointment request form to reach out today. We’re a family-run business with a commitment to providing the absolute best service to our neighbors throughout Indianapolis and the surrounding communities and we’re honored to be of service to you and your family!


For many chimney relining problems, stainless steel liners could be your best option. Ask our pros for more information.