The purpose of a chimney flue is to route the smoke and by-products of combustion safely out of the fireplace, stove or insert. Since these by-products of combustion are toxic and extremely hot, the NFPA 211 Code requires that every appliance needs a sound and in-tact chimney liner to contain and expel these volatiles to the atmosphere. A chimney liner needs to be free of cracks or holes that may cause serious trouble. Chimney liners protect the walls of the chimney from the intense high temperatures and harsh by-products from combustion that can harm the structural integrity of the chimney.
Many liners are constructed of clay tiles. These tiles and the mortar joints between them, can deteriorate over time and often require replacement. To replace a clay tile chimney liner with another liner can be a difficult project depending on site conditions and how easily the old liner can be removed. A missing or damaged chimney liner is a serious problem that can have catastrophic results if left ignored.
Stainless steel chimney liners may be an option to consider when relining a chimney. This single wall, stainless steel pipe must match the venting output requirements of your appliance or fireplace to work properly. This chimney liner can be flexible or rigid stainless steel. In some circumstances, this type of liner may be wrapped with ceramic fiber insulation for better performance.
Using an unlined masonry chimney will result in deteriorated chimney walls, sometimes to the extent that bricks will actually fall. Chimney Specialists highly recommends the AHRENS Chimney Lining "cast-in-place" technique to both repair and prevent structural problems. Some type of chimney liner is necessary for every chimney but the AHRENS process will reinforce the structure while ensuring the safety of your home and loved ones. The AHRENS Chimney Technique uses a highly insulative mortar-like mixture. This “first liner” is poured into the chimney and a vibrating form is slowly raised up. This will completely fill any deteriorated mortar joints, cracks or crevices. This first-liner is mixed to a zero-slump consistency, so it will not cave-in as the form is pulled up.
AHRENS is listed for use with all fuels; wood, gas, oil & coal. Depending on the size needed, flue forms are available from 4 inches to 4 feet in diameter and also in equivalent oblong shapes to fit rectangular chimneys. AHRENS can be used for residential applications and commercial and industrial chimneys to heights of 250'. The continuous poured liner provides increased strength to any masonry chimney. The AHRENS liner is installed in one continuous pour which means there are no seams or joints to leak or separate. AHRENS can prevent the need to tear down deteriorated chimneys, thus allowing the exterior appearance to remain the same, a particularly important consideration for historical projects. The AHRENS process will also allow “zero clearance” from the chimney to combustibles such as the roof rafters, without resulting in a fire hazard.
The unlined chimney in this picture has collapsed as a result of ignoring serious deterioration. Major damage to the home could have been avoided with the AHRENS chimney technique in place to protect and strengthen the chimney structure. We handle all types of chimney problems, from drastic structural issues like this one to others that are less severe. Whatever your needs our chimney professionals are qualified and ready to help.
Other problems made worse by the absence of a chimney liner include harmful gases entering the chimney and mixing with moisture. The moisture can then seep into the porous brick and cause rapid deterioration. When the temperature freezes, the water expands and causes the face of the bricks to fall off. This process is called “spalling”. This can lead to structural problems if left unresolved. To prevent these problems and make repairs where necessary, contact the chimney professionals in Highland, Wisconsin at Chimney Specialists.
This picture shows a fireplace that was not properly installed. Proper clearances to the combustible wood siding were not maintained. The black charring on the wood panels is from “pyrolysis”. This occurs when the combustible material is subjected to heat over time and the ignition temperature of the wood is actually lowered. This wood will ignite with temperatures as low as 250° Fahrenheit. It is absolutely critical for proper clearances be met or exceeded. The AHRENS Technique would have prevented this from happening.
At Chimney Specialists Inc., our team has received a long list of recognitions for our work with chimney repairs in southwest Wisconsin, northeast Iowa and northwest Illinois. We have received ten “Outstanding Customer Service and Satisfaction” awards. We have been recognized six times as the “Outstanding Chimney Restoration Company” in the United States at the National AHRENS Convention. We also held the U.S. record for AHRENS’ largest diameter cast-in-place industrial liner for 5 years, a 32" diameter pour!
Any company can install a chimney liner in your home, but not everyone can install it correctly.
Have your chimney liner installed properly by a fully insured, certified and reputable company.
Since 1977 Chimney Specialists Inc. in Highland Wisconsin - Call us at (800) 395-6660.