We Use Thermocrete
Ceramic Flue Sealant is the most reliable solution for chimney 
restoration and chimney repair. The Thermocrete process coats the inside of the chimney from top to bottom with a highly durable ceramic sealant. It is cost effective and ideal for use in your fireplace chimney, and in chimneys serving gas, oil, wood, or coal burning appliances.
The coating seals all small holes and cracks, strengthens the chimney, and increases efficiency without downsizing the flue significantly.
Thermocrete Ceramic Flue Sealant (CFS) is a chimney restoration and chimney repair product designed for all types of masonry chimneys. The patented Ceramic Flue Sealant material:
- Withstands extremely high temperatures
- Eliminates the need to downsize the flue substantially
- Keeps costs contained, even for multiple-flue chimneys
- Increases structural stability
- Withstands corrosive elements that damage many types of liners
Thermocrete is the premier solution for chimney repair and chimney restoration. With our advanced spray technology, several layers of ceramic flue sealant are sprayed inside each flue. This coating seals all small holes and cracks, strengthens the chimney, flue, and increases efficiency without making it significantly smaller.
Thermocrete Ceramic Flue Sealant is applied in a semi-liquid form, providing excellent adhesion to masonry surfaces, coating the entire interior surface of the flue, and filling small gaps in the masonry work with a fireproof seal. Multiple layers of the ceramic material are applied, forming a complete and durable chimney sealant, unsurpassed in the industry.
Thermocrete Ceramic Flue Sealant Data Sheet
| Bulk Density | 1800 kg/m3 |
| Cold Crushing Strength | 3800 psi |
| Maximum Service Temperature | 1600°c |
| Average Thermal Conductivity | 0.7 w/ (m k) |
| Permanent Linear Change at 1,000°c | 0.1 % |
| Acid Resistance Loss by Weight | 0 % |
| Abrasion Resistance | High |
| Gas Permeability | 0% |
| Sweep Test Lost by Weight | 0.7% |
| Freeze/Thaw Weight Loss | 1.75% |
| Packaging | 50 lbs./plastic pail |
Thermocrete Ceramic Flue Sealant is an aluminum-silica base castable refractory tested by Warnock Hersey / Intertek Testing Services (#J99001572-231). CFS is produced to B.S. 4207 and tested by the Ceramics Institute/CERAM Research (NAMAS) to B.S. 1902. Thermocrete products are accepted for use in 82 countries worldwide.
American Standard for Testing and Materials (ASTM)
& Underwriters Laboratory (UL)
| ASTM C20- Apparent Porosity | UL 1777 Section 4- Components |
| ASTM C113- Permanent linear change | UL 1777 Section 13- General |
| ASTM C133- Cold Crushing Strength | UL 1777 Section 22- Strength Tests |
| ASTM C24- Refractoriness PCE | UL 1777 Section 23- Sweep Tests |
| ASTM C24 & ASTM C113- Max. Temp | UL 1777 Sec 28- Resistance to Acids |
| UL 1777-Section 1- Scope | UL 1777 Sec 29- Freeze/Thaw Cycle |
| UL 1777-Section 2- General | UL 1777 Section 31- Marking |
| UL 1777-Section 3- Glossary | UL 1777 Sec 32- Inst. & Maint. |
(CICS) Certificate Number 93158, to the requirements of American National Standards Institute (ANSI), and American Society for Quality Control (ASQC) Q 9002, EN-ISO-9002. (UK OPS)
Read the Thermocrete™ Ceramic Flue Sealant Technical Data Sheet as a PDF.
