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HeatShield® Cerfractory Flue Sealant

Historically when gaps between flue tiles (deteriorated or missing mortar joints) or cracks in the flue tiles themselves were discovered, the only way to repair them was to completely remove the flue tiles and replace them with a stainless steel liner. Unfortunately, there was no way to reach down inside the chimney and re-pack the missing mortar joints or repair cracked flue tiles….until now!


HeatShield® is the answer to repacking deteriorated mortar joints and resurfacing cracked flue tiles at a fraction of the cost of relining with stainless steel!!

Are There Hidden Dangers In Your Chimney?

Gaps between flue tiles and missing mortar joints are potentially very dangerous and should be repaired immediately.

Gaps between flue tiles and missing mortar joints are potentially very dangerous and should be repaired immediately.

Gaps Between Flue Tiles: The combustion process creates noxious gases that can contain creosote/soot, carbon monoxide, and corrosive chemicals. The purpose of your chimney is to safely vent these hazardous flue gases from your home.

Flue Tiles are typically sealed with mortar to keep these gases contained within the flue. But over time, the mixture of rainwater, heat and chemicals can erode the mortar between the tiles, leaving potentially dangerous gaps or voids.

Cracks in the flue tiles are potentially hazardous, no matter how small. Even hairline cracks can open wide while the flue tile expands as it is subjected to heat.

Cracks in the flue tiles are potentially hazardous, no matter how small. Even hairline cracks can open wide while the flue tile expands as it is subjected to heat.

Cracked Flue Tiles: Flue tiles can crack due to “sudden occurrences” such as a previous chimney fire, lightning strike or seismic event.

Cracks may also be caused by poor workmanship or the ongoing settling of your home.

Why Are Gaps and Cracks Dangerous?

Open gaps between flue liners can be disastrous.

Open gaps between flue liners can be disastrous.

These defects, no matter how small, can begin a process that will further erode the chimney and can pose a threat to your family’s health. When heat, moisture, and gases escape through gaps and cracks in your chimney, they can deteriorate your chimney from the inside out.

More importantly, the gaps and cracks can cause health risks by allowing poisonous gases to escape into your home.

Combustible creosote or soot can also escape through these openings and build up outside the flue liner. If the creosote were to catch fire in this area of your chimney, serious damage can occur, because the fire can no longer be contained within the flue!

HeatShield® Restores The Integrity Of Your Chimney

HeatShield Diagram

HeatShield Diagram

HeatShield® is a specially formulated “cerfractory” sealant that restores the integrity of your chimney’s flue to vent hazardous flue gases from your home. Developed in Europe over 20 years ago, HeatShield®’s cerfractory technology is a hybrid (ceramic/refractory) coating that has been proven to withstand moisture, corrosive flue gases, and temperatures in excess of 2900 degrees Fahrenheit!

It eliminates the dangers in your chimney caused by gaps, cracks, and spalling for years to come. With a 20 year warranty, it has been independently tested to exceed all ASTM (American Society for Testing and Materials) and UL (Underwriters Laboratories –UL2425) standards for chimney repair and resurfacing products.



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Dear A to Z Chimney

I just wanted to thank you from the bottom of my heart for the great service you have done for me. I am an avid wood burner and love to burn my fires just about every evening. There’s nothing like the simple pleasure of curling up next to a warm and cozy fire during those cold winter nights.

Unfortunately, I had a chimney fire which did extensive damage to my chimney and it had to be re-lined with a new Stainless Steel Liner.

Last year, I hired a different company to come out and sweep my chimney. The sweep from that company tried to use high pressure sales tactics to get me to do the repairs. His poor attitude and high pressure turned me off so badly that I decided not to have them do the work.

This year, I hired your company and Chris Donovan was such a gentleman! He gave me the same bad news, but this time I could see it with my own eyes on the screen as he video scanned my flue. He was also much more knowledgeable and informative and really took the time to help me understand. He did not talk condescendingly, and there was no pressure whatsoever.

Consequently, I did hire your company to come back and complete the needed repairs, and was absolutely delighted!! Not only did Chris come back, but Aaron, the owner came, as well. I was delighted to know that the owner was personally seeing to the work. In the process of repairing my chimney, some other minor problems were detected, and they fixed them at no additional charge!

In addition, when everything was done, they did a spectacular job cleaning up every bit of their mess, and I couldn’t even tell they had been here.

Thanks again for the great service you provide! I will use you again and again, and refer you to my friends.


~ Beverly Bland, Carmichael, CA
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