Security Chimneys


Security Chimneys TMXBAG TherMix

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Since starting operations in 1960, Security Chimneys International has built a reputation as one of the most trusted suppliers of quality chimneys in North America. Our dedication to total quality lives in the research and development of new products and services for the residential and commercial markets. With a 104,800-square-foot manufacturing facility in Laval, Quebec, we are fully equipped and accredited to certify that all our products are in accordance with UL and ULC standards.
Throughout our history, our product offerings have evolved. We’ve strengthened our focus on maintaining our leadership position in the industry by designing, building, and marketing a complete line of chimneys for residential and commercial applications that have set the standard that other manufacturers have often imitated, but never equaled.

Ultimately, Security Chimneys International believes that quality relationships develop quality products. We have developed valuable partnerships by providing superior sales support, customer service, and products. But most of all, we’ve fostered an environment where customer focus is the key to our success.

Why Choose Security Chimneys?

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For over 50 years, Security Chimneys has been an innovator in the venting field and a market leader in North America. Instrumental in the company’s growth has been an ongoing focus on product improvement and the introduction of new, innovative products. This drive for excellence has given rise to the Tubinox venting system, a line of high-quality products that deliver optimal performance.


Time and wear can crack clay liners. Under these conditions, your liner can quickly become a nest for creosote deposits. Should this be the case with your masonry chimney, it would be wise, for safety reasons, to consider the advantages of a TUBINOX stainless steel liner. The accumulation of creosote inside a chimney can become dangerous. As it is inflammable, creosote is the cause of chimney fires which can spread to become a real danger. The stainless steel liner impedes the adhesion of creosote.


Controlled combustion stoves are designed accordingly to highly efficient heat transfer and combustion technologies. Their rate of performance increases when they are installed with a chimney of suitable diameter. Clay liners are often too large. Consequently, they remain too cold and do not allow gas to be completely consumed, a situation that leads to gas condensation, thus the formation of creosote.



  • Use to fill space between a liner and inside masonry chimney.
  • Ready-mix formula cures into a lightweight semi-hard mass that insulates the liner and dissipates the intense heat created in a chimney fire.



Piece/carton 1


*Use Table 1 to estimate the number of TherMix bags or boxes needed to do the job.
  • Find the flue opening that comes closest to the one being lined, the left-hand column.
  • Find the size of the liner to be installed across the top line.
  • Where the values intersect, read the cubic foot volume of TherMix per foot of chimney height.
  • Multiply this volume by the height (in feet) of the chimney.
  • Divide the cubic feet calculated in the previous step by 3.25. This answer will determine the number of bags/boxes of TherMix needed.



A 28' chimney with a flue opening of 8.5" x 8.5" is to be lined with a 6" liner. As shown in Table 1, .30ft3 of TherMix is needed per foot of chimney height. Multiply .30 by 28 (the height of the chimney), to get 8.4ft3 . Now divide 8.4 by 3.25 (the approximate volume yield per bag of TherMix), to obtain 2.6 bags/boxes of TherMix to complete the installation. *Masonry chimneys are not uniform structures. Have extra bags/boxes available in case you need them. If there is an installation not covered by table 1, refer to the formula below:



W = Width of masonry flue opening (in inches)
D = Depth of masonry flue opening (in inches)
H = Height of masonry flue (in inches)
CS =  Cross Section areas of chimney liner (table 2)